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Expressão gênica do receptor de IGF-1 em células da granulosa luteinizadas de mulheres com síndrome dos ovários policísticos (SOP), não obesas, com sensibilidade à insulina normal, tratadas e não tratadas com metformina / Gene expression of the IGF-1 receptor in luteinized granulosa cells from non-obese women with polycystic ovarian syndrome (PCOS) and with normal insulin sensitivity, treated or not withmetforminSantana, Laura Ferreira 09 August 2007 (has links)
OBJETIVO: avaliação da expressão gênicado receptor do fator de crescimento semelhante à insulina de (Insulin-Like Growth Factor- IGF) 1 em células da granulosa luteinizadas do cumulusde mulheres não obesas, com sensibilidade à insulina normal, com síndrome dos ovários policísticos (SOP) tratadas e não tratadas com metformina. MODELO DO ESTUDO: prospectivo, longitudinal, randomizado. PACIENTES E MÉTODOS: avaliamos 12 mulheres com ciclosovulatórios, 9 mulheres com SOP e 8 mulheres com SOP e tratadas com metformina, ao menos 8 semanas na dose de 1.700 mg/dia. Todos os grupos foram similares com relação ao peso, ao índice de massa corporal (IMC), à circunferência da cintura e com sensibilidade à insulina normal. Todas as mulheres foram submetidas à estimulação ovariana controlada com uso de agonista de GnRH em protocolo longo e gonadotrofinas para ciclos de FIV/ICSI. As células da granulosa do cumulusforam obtidas por microdissecção dos cinco maiores folículos pré-ovulatórios. A expressão gênica do receptor de IGF-1 foi determinada com técnica da Reação da Polimerase em Cadeia a partir da Transcrição Reversa (Reverse transcriptase - Polymerase Chain ReactionRT-PCR) emiquantitativa. Foram avaliadas as concentrações séricas e foliculares de estradiol, progesterona, testosterona, hormônio folículo estimulante (Follicle-Stimulating Hormone- FSH), hormônio luteinizante (Luteinizing Hormone - LH), Sex Hormone-Binding Globulin(SHBG), glicose, insulina e IGF-1. Para análise estatística, foram utilizados os testes: ANOVA, Newman-Keuls, coeficiente de Pearsone regressão linear múltipla, sendo considerado nível de significância de 5%. RESULTADOS: não foram observadas diferenças com relação à expressão gênica do receptor de IGF-1 nos três grupos analisados (P>0,05). O número de oócitos (20,4 vs. 13,1 vs.11,5, P= 0,009), os níveis séricos de estradiol (1.896,00 pcg/mL vs. 985,20 pcg/mL vs.908,10 pcg/mL,P = 0,03) e testosterona (1,43 ng/mL vs.0,89 ng/mL vs. 0,82 ng/mL pcg/mL,P = 0,02) foram maiores no grupo de mulheres com SOP não tratadas com metformina em comparação com as mulheres com ciclos ovulatórios e tratadas com metformina, respectivamente. As mulheres com ciclos ovulatórios (50.710±42.520 ng/mL) apresentaram maiores concentrações foliculares de progesterona quando comparados com as mulheres com SOP tratadas (13.660±5.212 ng/mL) e não tratadas com metformina (17.680±6.644 ng/mL) (P=0,01). Na avaliação da regressão múltipla, a testosterona sérica não sofreu influência da expressão gênica do receptor de IGF-1 ou do IMC. CONCLUSÕES: as altas concentrações séricas de estradiol e testosterona, maior número de oócitos no grupo de mulheres com SOP não tratadas com metformina nos levam a concluir que mulheres com SOP provavelmente têm uma maior sensibilidade à estimulação da esteroidogênese ovariana quando comparadas com mulheres sem essa doença, embora não tenhasido encontrada diferença na expressão do receptor de IGF-1 nos trêsgrupos analisados. A similaridade dos resultados deste estudo entre mulheres com SOP tratadas com metformina e com ciclos ovulatórios nos levam a \"hipotetizar\" que um dos possíveis mecanismos de ação da metformina no sistema IGF-1 nas células da granulosa do cumulus poderia ser por mecanismos pós-receptores. / OBJECTIVE: evaluation of the gene expression of the IGF-I receptor in luteinized cumulus granulosa cells from non-obese women with normal insulin sensitivity and with polycystic ovarian syndrome (PCOS)treated or nor with metformin. STUDY MODEL: prospective,longitudinal, randomized. PATIENTS AND METHODS: we evaluated 12 women withovulatory cycles and 9 women with PCOS who had been treated for at least 8 weeks with a metformin dose of 1700 mg/day. All groups were similar interms of weight, body mass index (BMI), and waist circumference and all had normal insulin sensitivity. All women were submitted to controlled ovarian stimulation with a GnRH agonist in a long protocol and with gonadotropins for IVF/ICSI cycles. Cumulus granulosa cells were obtained by microdissection of the five largest pre-ovulatory follicles. Gene expression of the IGF-1 receptor was determined by semiquantitative RT-PCR. Serum and follicular concentrations of estradiol, progesterone, testosterone, FSH, LH, insulin, SHBG, and IGF-1 were determined. Data were analyzed statistically by ANOVA and by the Newman-Keuls test and the Pearson coefficient and linear multiple regression were calculated, with the level of significance set at 5%. RESULTS: no difference in geneexpression of the IGF-I receptor were observed between the three groups studied (P>0.05). The number of oocytes (20.4 vs. 13.1 vs. 11.5, P= 0.009) and the serum levels of estradiol (1,896.00 pcg/mL vs. 985.20 pcg/mL vs.908.10 pcg/mL,P = 0.03) and testosterone (1.43 ng/mL vs.0.89 ng/mL vs. 0.82 ng/mL pcg/mL,P = 0.02) were higher in the group of women with PCOS not treated with metformin than in women with ovulatory cycles and in women treated with metformin, respectively. The women with ovulatory cycles (50.710±42.520 ng/mL) presented higher follicular concentrations of progesterone compared with women with PCOS treated (13.660±5.212 ng/mL) or not with metformin (17.680±6.644 ng/mL) (P=0.01). Multiple regression revealed that serum testosterone was not affected by the gene expression of the IGF-1 receptor or by BMI. CONCLUSIONS: the high serum concentrations of estradiol and testosterone and the larger number of oocytes in the group ofwomen with PCOS not treated with metformin lead us to conclude that women with PCOS probably have greater sensitivity to stimulation ofovarian steroidogenesis than women without the disease, although no difference was detected in the expression of the IGF-I receptor between the three groups studied. The similarity ofthe present results for the women with PCOS treated with metformin and for the women with ovulatory cycles leads us to hypothesize that one of the possible mechanisms of action of metformin on the IGF-1 system in cumulus granulosa cells may be of the post-receptor type.
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Mécanismes de régulation de la balance prolifération/différenciation érythroïde par les facteurs de transcription GATA-1, FOG-1, E2F et la voie de signalisation Akt / Control mechanisms of the balance between proliferation and erythroid differentiation by transcription factors GATA-1, FOG-1, E2F and Akt signaling pathwayLefevre, Carine 18 March 2013 (has links)
Avec plus de 100 milliards de globules rouges produits chaque jour, le lignage érythroïde présente la plus grande capacité de production cellulaire chez le mammifère adulte. Cette production requiert une balance fine entre la prolifération cellulaire, régulée principalement par la voie de signalisation érythropoïétine (Epo)/PI3K/Akt, et la différenciation érythroïde induite par le couple de facteurs de transcription GATA-1/FOG-1. Des interconnexions entre ces deux grands systèmes ont été décrites dans le laboratoire : 1) le facteur de transcription GATA-1 est phosphorylé par Akt en réponse à l’Epo et cette phosphorylation semble avoir un rôle dans la différenciation érythroïde ; 2) GATA-1 est capable d’interagir avec la protéine du rétinoblastome pRb, impliquée dans la régulation du cycle cellulaire, et le complexe formé est nécessaire à l’érythropoïèse terminale.L'objectif de ma thèse était d’étudier les mécanismes moléculaires impliqués dans la balance prolifération/différenciation cellulaire au cours de l’érythropoïèse, et en particulier de déterminer le rôle moléculaire et physiologique de la phosphorylation de GATA-1 par Akt en réponse à l’Epo. Nos travaux ont montré que cette phosphorylation est une des clefs de la dynamique de l’érythropoïèse. Dans sa forme non phosphorylée, GATA-1 ralentit le cycle cellulaire via le complexe GATA-1/pRb/E2F. Cette étape préliminaire est nécessaire à la mise en place de la différenciation érythroïde terminale. La phosphorylation de GATA-1 induit d’une part la dissociation de GATA-1/pRb/E2F favorisant l’expansion cellulaire, et d’autre part la formation du complexe GATA-1/FOG-1 nécessaire à l’activation des gènes érythroïdes. Ce modèle apporte une explication moléculaire au blocage de la différenciation érythroïde terminale induite par le mutant GATA-1V205G qui n’interagit pas avec FOG-1. Ainsi, la phosphorylation constitutive de GATA-1V205G et l’augmentation de la quantité relative de FOG-1 permettent de restaurer la différenciation érythroïde induite par ce mutant in vitro. Enfin, l’étude d’un modèle murin exprimant une protéine GATA-1 non phosphorylable par Akt montre l’apparition d’une anémie létale lorsque la voie IGF-1 est inhibée. Cela démontre l’importance de la dynamique moléculaire induite par la phosphorylation de GATA-1, et met en évidence le rôle majeur de l’IGF-1 dans l’érythropoïèse in vivo.En conclusion, nous proposons un nouveau modèle moléculaire de la régulation de la balance prolifération/différenciation érythroïde dans lequel la phosphorylation de GATA-1 par Akt coordonne la distribution de GATA-1 dans deux complexes protéiques fonctionnels différents : GATA-1/pRb/E2F versus GATA-1/FOG-1. Nous mettons également en évidence l’IGF-1 comme acteur central de la compensation mise en place in vivo pour pallier à l’absence de phosphorylation de GATA-1. / With more than 100 billion red blood cells generated every day, the erythroid lineage has the largest output of cell production in adult mammals. This production requires a tight balance between cell proliferation, mainly controlled by erythropoietin (Epo)/PI3K/Akt signaling pathway, and erythroid differentiation induced by GATA-1 and FOG-1 transcription factors. Various links between these two processes have been previously demonstrated in the laboratory: 1) Epo-activated Akt directly phosphorylates GATA-1 transcription factors, and this phosphorylation seems to be involved in erythroid differentiation; 2) GATA-1 binds to the cell cycle regulator retinoblastoma protein (pRb), and the resulting complex is essential for terminal erythropoiesis.We investigated the molecular mechanisms involved in the cell proliferation/differentiation balance during terminal erythropoiesis; in particular, we studied the molecular and physiological role of Epo-induced GATA-1 phosphorylation. Our findings suggest that this phosphorylation is one of the key processes in erythropoiesis dynamics. In its unphosphorylated form, GATA-1 can break cell cycle progression via GATA-1/pRb/E2F complex. This preliminary step is necessary for terminal erythroid differentiation. GATA-1 phosphorylation promotes GATA-1/pRb/E2F dissociation, allowing cell cycle progression, and GATA-1/FOG-1 binding, necessary to activate erythroid genes. Our model provides a molecular explanation for the arrest of terminal erythroid differentiation observed in the non-FOG-1-binding mutant GATA-1V205G. We show that the constitutive phosphorylation of GATA-1V205G and the increase of FOG-1 protein amount rescue erythroid differentiation in vitro. Finally, knock-in expression of unphosphorylatable GATA-1 in mice leads to lethal anemia when the IGF-1 signaling pathway is inhibited. This shows the importance of the molecular dynamics of GATA-1 phosphorylation, and highlights the major role of IGF-1 in erythropoiesis, in vivo.In conclusion, we propose a new molecular model for the control of the balance between proliferation and erythroid differentiation. GATA-1 phosphorylation by Akt coordinates the involvement of GATA-1 in two different functional protein complexes: GATA-1/pRb/E2F and GATA-1/FOG-1. We also highlight the major role of IGF-1 in compensating for the lack of GATA-1 phosphorylation in vivo.
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CÂNCER DE TIRÓIDE EM PACIENTES COM ACROMEGALIA: UM ESTUDO CASO-CONTROLE / THYROID CANCER IN PATIENTS WITH ACROMEGALY: A STUDY OF CASE-CONTROLSantos, Maíra Cristina Carvalho dos 18 June 2012 (has links)
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Previous issue date: 2012-06-18 / Several studies have associated acromegaly with an increased risk of benign and
malignant tumors. While simple and multinodular goiters are common findings in
acromegaly, the prevalence of thyroid cancer is uncertain. The objective of this study
was to estimate the prevalence of thyroid cancer in a series of acromegalic patients
from three hospitals in northeast of Brazil. The methodology used included
morphological, cytological and histological thyroid analysis of acromegalic patients
and volunteers over 18 years, matched for age and sex and with nodule (s) ≥ 1 cm.
The subjects of this study were 124 acromegalic patients, including 76 females
(61.3%) and 48 men (38.7%), with a mean age 45.1 years. Results of the study
showed that thyroid ultrasonography was normal in 31 cases (25%), 25 had diffuse
goiter (20.1%), 67 had nodules (54%) and one agenesis of the right lobe (0.8%).
Thirty six patients underwent fine needle aspiration biopsy (FNAB) of their nodules
and 9 cases of papillary cancer were found (7.2%). The control group consisted of
263 subjects, 156 females (59.3%) and 107 males (40.7%), mean age 44.7 years. In
ultrasound assessment, 96 had nodules (36.5%). Of these, 13 were punctured and 2
cases of papillary carcinoma were found (0.7%). These results gave an odds ratio of
10.21 (p = 0.0011, 95% CI 2.17 to 48.01). These findings demonstrate an increased
prevalence of thyroid cancer, statistically significant when compared to our control
group. Thus, it is suggested that acromegalic patients should be routinely submitted
to thyroid ultrasound evaluation, followed by FNAB of nodules when indicated. / Vários estudos têm associado acromegalia a um risco aumentado de tumores
benignos e malignos. Enquanto bócios simples e multinodulares são achados
comuns em acromegálicos, a prevalência de câncer de tireóide é incerta. O objetivo
deste estudo foi estimar a prevalência de câncer de tireóide em uma série de
pacientes com acromegalia de três hospitais do nordeste brasileiro. A metodologia
utilizada incluiu a análise morfológica, citológica e histopatológica da tiróide de
pacientes acromegálicos e voluntários com mais de 18 anos, pareados por idade e
sexo e com nódulo (s) ≥ 1 cm. Foram avaliados 124 pacientes com acromegalia,
incluindo 76 mulheres (61,3%) e 48 homens (38,7%), com idade média de 45,1
anos. Ao estudo ultrassonográfico da tiróide evidenciou-se normalidade em 31 casos
(25%), 25 tinham bócio difuso (20,1%), 67 apresentavam nódulos (54%) e um
agenesia do lobo direito (0,8%). Trinta e seis pacientes foram submetidos a biópsia
aspirativa por agulha fina (PAAF) de seus nódulos e 9 casos de carcinoma papilífero
foram encontrados (7,2%). O grupo controle consistiu de 263 indivíduos, 156 do
sexo feminino (59,3%) e 107 do sexo masculino (40,7%), com idade média de 44,7
anos. Na avaliação ultrassonográfica, 96 apresentavam nódulos (36,5%). Destes, 13
foram puncionados e 2 casos de carcinoma papilífero foram encontrados (0,7%).
Estes resultados conferiram um odds ratio de 10,21 (p = 0,0011, IC 95% 2,17-
48,01). Estes resultados demonstraram uma prevalência aumentada de câncer de
tiróide, estatisticamente significativa, quando comparado ao nosso grupo controle.
Desta forma, sugere-se que pacientes acromegálicos devam rotineiramente ser
submetidos a exame ultrassonográfico da tiróide, seguido por PAAF de nódulos
quando indicado.
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Estudo da associaÃÃo entre a acromegalia e a presenÃa da mutaÃÃo BRAFV600E e a expressÃo imunohistoquÃmica de IGF-1 e galectina-3 no carcinoma papilÃfero de tireoide. / Study of the association between acromegaly and the presence of BRAFV600E mutation and immunohistochemical expression of IGF-1 and galectin-3 in papillary thyroid carcinoma.Renan MagalhÃes Montenegro 31 August 2012 (has links)
nÃo hà / INTRODUÃÃO: Estudos epidemiolÃgicos sugerem que o carcinoma de tireoide seja a neoplasia maligna mais frequente nos pacientes acromegÃlicos. Atà este momento nÃo hà relatos de estudos avaliando marcadores moleculares do carcinoma papilÃfero de tireoide (CPT) nessa populaÃÃo. OBJETIVOS: Avaliar a associaÃÃo entre acromegalia, presenÃa da mutaÃÃo BRAFV600E, marcadores imunohistoquÃmicos (galectina-3 e IGF-1) e caracterÃsticas clÃnico-patolÃgicas em pacientes acromegÃlicos com CPT. MATERIAL E MÃTODOS: Trata-se de um estudo transversal realizado no perÃodo de janeiro/09 a dezembro/2011, onde 11 pacientes acromegÃlicos com CPT, provenientes de 5 centros brasileiros de referÃncia no tratamento da acromegalia foram comparados com 45 pacientes com CPT sem acromegalia. Foram estudadas variÃveis clÃnicas e histopatolÃgicas do CPT. Utilizou-se cortes histolÃgicos de CPT emblocados em parafina para o estudo da mutaÃÃo BRAFV600E e para a anÃlise imunohistoquÃmica dos marcadores IGF-1 e galectina-3. Na anÃlise utilizou-se os testes t de student e do qui-quadrado (software SPSS, versÃo 13.0 para Windows) (p<0,05). RESULTADOS: A idade mÃdia dos pacientes acromegÃlicos com CPT foi de 61,5  6,02 anos, sendo 72,7% do sexo feminino. O tempo mÃdio de diagnÃstico da acromegalia foi de 7,7  3,90 anos, sendo o intervalo entre o diagnÃstico da acromegalia e do CPT, em mÃdia, 3,4  2,71 anos. Os nÃveis sÃricos de IGF-1 dos acromegÃlicos ao diagnÃstico do CPT foi de 417,0 ng/mL. NÃo houve diferenÃa quanto ao estadiamento TNM (Tumor, Nodule, Metastasis) e Ãndice prognÃstico AMES (Ages, Metastasis, Extent, Size) entre os grupos. Houve maior prevalÃncia da mutaÃÃo BRAFV600E (90,9% vs 55,6%; p=0,039) e de forte imunoexpressÃo para IGF-1 (88,9% vs 38,1%; p= 0,017) nos acromegÃlicos. NÃo houve diferenÃa na expressÃo de galectina-3 entre os grupos. CONCLUSÃO: Neste trabalho, pela primeira vez se mostrou uma alta prevalÃncia da mutaÃÃo BRAFV600E em CPT de acromegÃlicos, muito superior à descrita na populaÃÃo com CPT neste e em estudos anteriores (cerca de 40%). Contudo essa mutaÃÃo nÃo se mostrou associada a um fenÃtipo mais agressivo do tumor, o que diverge dos achados em populaÃÃo nÃo acromegÃlica com CPT. Conclui-se que a acromegalia à possivelmente associada à mutaÃÃo BRAFV600E em pacientes acromegÃlicos com CPT. Novos estudos serÃo necessÃrios para definir os mecanismos responsÃveis por tal associaÃÃo. / INTRODUCTION: Epidemiological studies suggest that thyroid carcinoma is the most common malignant neoplasm in acromegalic patients. At this moment there are no reports of studies evaluating molecular markers of papillary thyroid carcinoma (PTC) in this population. OBJECTIVES: The present work aimed to evaluate the association between acromegaly, expression of the mutation BRAFV600E, immunohistochemical markers (galectin-3 and IGF-1), and clinical-pathological characteristics in acromegalic patients with PTC. MATERIALS AND METHODS: This is a cross-sectional study conducted from January/09 to December/2011, where 11 acromegalic patients with CPT, from 5 Brazilian centers of reference in the treatment of acromegaly were compared with 45 patients with acromegaly without PTC. We evaluated clinical and histopathological variables of PTC. We used histological PTC embedded in paraffin for mutation study BRAFV600E and immunohistochemical analysis of markers IGF-1 and galectin-3. In the analysis we used the Student t test and chi-square test (SPSS software, version 13.0 for Windows) (p <0.05). RESULTS: The average age of acromegalic patients with PTC was 61.5  6.02 years and 72.7% were female. The average time of diagnosis of acromegaly was 7.7  3.90 years, and the interval between diagnosis of acromegaly and PTC was an average 3.4  2.71 years. The serum levels of IGF-1 in the diagnosis of acromegaly PTC was 417.0 ng / mL. There was no difference in the TNM (Tumor, Nodule, Metastasis) and AMES prognostic index (Ages, Metastasis, Extent, Size) between groups. There was a higher prevalence of the BRAFV600E mutation (90.9% vs 55.6%, p = 0.039) and stronger immunohistochemical expression for IGF-1 (88.9% vs 38.1%, p = 0.017) in acromegaly. There was no difference in the expression of galectin-3 between the groups. CONCLUSION: This work for the first time showed a high prevalence of mutations in BRAFV600E in PTC of acromegalic patients superior to those described in the population with PTC in this and previous studies (approximately 40%). However, this mutation was not associated with a more aggressive tumor phenotype, which differs from the findings in acromegalic population without PTC. We conclude that acromegaly is possibly associated to a mutation BRAFV600E in acromegalic patients with CPT. Further studies are needed to define the mechanisms responsible for this association.
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Efeitos da suplementação crônica de L-arginina sobre a expressão de proteínas envolvidas na regulação da síntese proteica muscular em ratos treinados em exercícios de alta intensidade / Effects of chronic supplementation of L-arginine on the expression of proteins involved in the regulation of muscle protein synthesis in muscle of trained rats in high-intense Exercise.Mariana de Rezende Gomes 12 April 2013 (has links)
A arginina é um aminoácido condicionalmente essencial que participa de inúmeras reações metabólicas no organismo como, por exemplo, o ciclo da uréia, a síntese de creatina e a geração de óxido nítrico (NO). Além dessas funções a arginina é associada, com a sensibilidade à insulina, a secreção de GH e mais recentemente com a síntese protéica muscular. O objetivo deste trabalho foi investigar o efeito da suplementação via oral crônica de L-arginina sobre a síntese protéica muscular, pela via da mTOR, a fim de contribuir com as novas discussões científicas acerca deste aminoácido de ampla atuação. Métodos: Foram utilizados ratos wistar machos adultos com cerca de 200g de peso corporal divididos em quatro grupos de quatorze animais denominados na seguinte forma: Arginina Treinado (AT), Arginina Sedentário (AS), Dieta-Controle Treinado (CT) e Dieta-Controle Sedentário (CS). Ambas as dietas foram elaboradas com base das recomendações da AIN-93, sendo que a dieta enriquecida com arginina recebeu acréscimo de 2% deste aminoácido e a dieta controle recebeu um mix de aminoácidos não essenciais para garantir que ambas fossem isonitrogenadas e isocalóricas e as proporções de aminoácidos presente nas rações foi conferida por aminograma. O treinamento dos animais consistiu em exercício anaeróbio com sessões que eram compostas de 4 séries de 10 saltos com um minuto de descanso entre estas em tanque de água. Os saltos eram desempenhados com carga de 50% do peso corporal acoplado ao tórax dos animais na freqüência de 5 dias por semana por 6 semanas. A evolução da massa corporal dos animais bem como o consumo de ração foram avaliadas três vezes por semana e estimada uma média semanal. Foram realizados testes de tolerância oral à glicose (OGTT) e tolerância à insulina (ITT) no início e ao final do experimento em todos os animais para avaliar alterações na sensibilidade à insulina. Após 72hs da última sessão de treinamento os animais foram anestesiados para infusão de insulina, coleta dos músculos gastrocnêmio e plantar, fígado, sangue e eutanasiados conforme protocolo aprovado pelo CEA-USP. As análises bioquímicas foram determinações séricas de insulina, GH, IGF-1 e a proteína transportadora de IGF-1 (IGFBP-3), glicose plasmática, uréia e creatinina séricas, IGF-1 muscular e hepático por kits comerciais de tecnologia multiplex Luminex e aminograma sérico por cromatografia. As análises moleculares foram realizadas para as proteínas chaves envolvidas na via de síntese protéica muscular em sua forma total e fosforilada, sendo estas: IRS-1, Akt, mTOR, 4E-BP1 e p70S6K determinadas por método de western blotting. Resultados: Não foram encontradas diferenças estatisticamente significativas nos parâmetros avaliados com exceção da creatinina que se mostrou mais elevada nos grupos suplementados com arginina. A suplementação de arginina, nas concentrações administradas, bem como o exercício de alta intensidade pelo período determinado não foram capazes de alterar a expressão das proteínas envolvidas na regulação de síntese protéica muscular de ratos nem a sensibilidade celular à insulina. Conclusão: não houve aumento da síntese protéica muscular com a suplementação de arginina, nestas condições experimentais. / The arginine is an amino acid conditionally essential that participates in innumerous metabolic reactions in the body like, for instance, the urea cycle, the synthesis of creatine and production of nitric oxide (NO). Besides those functions the arginine is associated, with the insulin sensitivity, GH secretion and most recently with muscle protein synthesis. The aim of this work was to investigate the effect of L-arginine chronic oral supplementation on the muscle protein synthesis, through mTOR pathway, in order to contribute with new scientific discussions about this broad action amino acid. Methods: Wistar male adult rats were used with about 200g body weight distribute into four groups of fourteen animals named this way: Trained Arginine (TA), sedentary Arginine (SA), Trained Diet-Control (TC) and Sedentary Diet-control (SC). Both diets were elaborated based on the AIN-93 recommendations, considering that the enriched diet with arginine was added 2% of this amino acid and the control diet received a mix of non-essential amino acid in order to ensure that both were isonitrogenous and isocaloric and the proportions of present amino acids in the rations have been checked through aminogram. The animals training consisted of anaerobic exercise with sections composed by four jump series, with one minute rest among these in a PVC cube water. The jumps were performed with a load of 50% of their body weight attached in the animal\'s trunk, five days a week over six weeks. The animals\' body weight evolution as well as the food intake were evaluated three times a week in order to figure a weekly average. Oral glucose test tolerance (OGTT) and insulin test tolerance (ITT) have been done in the beginning and in the end of the experiment in all animals to evaluate insulin sensitive changes. The animals were anesthetized to insulin infusion, gastrocnemic and plantaris muscles, liver and blood collects 72 hrs after the last training section and afterwards sacrificed according to CEA-USP approved protocol. The biochemical analysis were blood determination of insulin, GH, IGF-1 and its binding protein 3 (IGFBP-3), glucose, urea and creatinine, and muscle and liver IGF-1 through commercial kits of multiplex Luminex technology and seric aminogram through chromatography. The molecular analysis were performed for the key proteins of the muscle protein synthesis pathway in its total and phosphorylated form: IRS-1, Akt-1, mTOR, 4E-BP1 and p70S6K determined by western blotting method. Results: Significant statistical differences were not found to all evaluated biomarkers in this experiment except for creatinine which was more elevated in groups supplemented with arginine. The arginine supplementation, in these given doses, as well as the high-intense exercise, failed in stimulate both the expression of the proteins involved in the muscle protein synthesis regulation and the insulin sensitivity in the rats in this condition. Conclusion: There hasn\'t been any increase in the muscle protein synthesis with arginine supplementation, in these experimental conditions.
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Expressão gênica do receptor de IGF-1 em células da granulosa luteinizadas de mulheres com síndrome dos ovários policísticos (SOP), não obesas, com sensibilidade à insulina normal, tratadas e não tratadas com metformina / Gene expression of the IGF-1 receptor in luteinized granulosa cells from non-obese women with polycystic ovarian syndrome (PCOS) and with normal insulin sensitivity, treated or not withmetforminLaura Ferreira Santana 09 August 2007 (has links)
OBJETIVO: avaliação da expressão gênicado receptor do fator de crescimento semelhante à insulina de (Insulin-Like Growth Factor- IGF) 1 em células da granulosa luteinizadas do cumulusde mulheres não obesas, com sensibilidade à insulina normal, com síndrome dos ovários policísticos (SOP) tratadas e não tratadas com metformina. MODELO DO ESTUDO: prospectivo, longitudinal, randomizado. PACIENTES E MÉTODOS: avaliamos 12 mulheres com ciclosovulatórios, 9 mulheres com SOP e 8 mulheres com SOP e tratadas com metformina, ao menos 8 semanas na dose de 1.700 mg/dia. Todos os grupos foram similares com relação ao peso, ao índice de massa corporal (IMC), à circunferência da cintura e com sensibilidade à insulina normal. Todas as mulheres foram submetidas à estimulação ovariana controlada com uso de agonista de GnRH em protocolo longo e gonadotrofinas para ciclos de FIV/ICSI. As células da granulosa do cumulusforam obtidas por microdissecção dos cinco maiores folículos pré-ovulatórios. A expressão gênica do receptor de IGF-1 foi determinada com técnica da Reação da Polimerase em Cadeia a partir da Transcrição Reversa (Reverse transcriptase - Polymerase Chain ReactionRT-PCR) emiquantitativa. Foram avaliadas as concentrações séricas e foliculares de estradiol, progesterona, testosterona, hormônio folículo estimulante (Follicle-Stimulating Hormone- FSH), hormônio luteinizante (Luteinizing Hormone - LH), Sex Hormone-Binding Globulin(SHBG), glicose, insulina e IGF-1. Para análise estatística, foram utilizados os testes: ANOVA, Newman-Keuls, coeficiente de Pearsone regressão linear múltipla, sendo considerado nível de significância de 5%. RESULTADOS: não foram observadas diferenças com relação à expressão gênica do receptor de IGF-1 nos três grupos analisados (P>0,05). O número de oócitos (20,4 vs. 13,1 vs.11,5, P= 0,009), os níveis séricos de estradiol (1.896,00 pcg/mL vs. 985,20 pcg/mL vs.908,10 pcg/mL,P = 0,03) e testosterona (1,43 ng/mL vs.0,89 ng/mL vs. 0,82 ng/mL pcg/mL,P = 0,02) foram maiores no grupo de mulheres com SOP não tratadas com metformina em comparação com as mulheres com ciclos ovulatórios e tratadas com metformina, respectivamente. As mulheres com ciclos ovulatórios (50.710±42.520 ng/mL) apresentaram maiores concentrações foliculares de progesterona quando comparados com as mulheres com SOP tratadas (13.660±5.212 ng/mL) e não tratadas com metformina (17.680±6.644 ng/mL) (P=0,01). Na avaliação da regressão múltipla, a testosterona sérica não sofreu influência da expressão gênica do receptor de IGF-1 ou do IMC. CONCLUSÕES: as altas concentrações séricas de estradiol e testosterona, maior número de oócitos no grupo de mulheres com SOP não tratadas com metformina nos levam a concluir que mulheres com SOP provavelmente têm uma maior sensibilidade à estimulação da esteroidogênese ovariana quando comparadas com mulheres sem essa doença, embora não tenhasido encontrada diferença na expressão do receptor de IGF-1 nos trêsgrupos analisados. A similaridade dos resultados deste estudo entre mulheres com SOP tratadas com metformina e com ciclos ovulatórios nos levam a \"hipotetizar\" que um dos possíveis mecanismos de ação da metformina no sistema IGF-1 nas células da granulosa do cumulus poderia ser por mecanismos pós-receptores. / OBJECTIVE: evaluation of the gene expression of the IGF-I receptor in luteinized cumulus granulosa cells from non-obese women with normal insulin sensitivity and with polycystic ovarian syndrome (PCOS)treated or nor with metformin. STUDY MODEL: prospective,longitudinal, randomized. PATIENTS AND METHODS: we evaluated 12 women withovulatory cycles and 9 women with PCOS who had been treated for at least 8 weeks with a metformin dose of 1700 mg/day. All groups were similar interms of weight, body mass index (BMI), and waist circumference and all had normal insulin sensitivity. All women were submitted to controlled ovarian stimulation with a GnRH agonist in a long protocol and with gonadotropins for IVF/ICSI cycles. Cumulus granulosa cells were obtained by microdissection of the five largest pre-ovulatory follicles. Gene expression of the IGF-1 receptor was determined by semiquantitative RT-PCR. Serum and follicular concentrations of estradiol, progesterone, testosterone, FSH, LH, insulin, SHBG, and IGF-1 were determined. Data were analyzed statistically by ANOVA and by the Newman-Keuls test and the Pearson coefficient and linear multiple regression were calculated, with the level of significance set at 5%. RESULTS: no difference in geneexpression of the IGF-I receptor were observed between the three groups studied (P>0.05). The number of oocytes (20.4 vs. 13.1 vs. 11.5, P= 0.009) and the serum levels of estradiol (1,896.00 pcg/mL vs. 985.20 pcg/mL vs.908.10 pcg/mL,P = 0.03) and testosterone (1.43 ng/mL vs.0.89 ng/mL vs. 0.82 ng/mL pcg/mL,P = 0.02) were higher in the group of women with PCOS not treated with metformin than in women with ovulatory cycles and in women treated with metformin, respectively. The women with ovulatory cycles (50.710±42.520 ng/mL) presented higher follicular concentrations of progesterone compared with women with PCOS treated (13.660±5.212 ng/mL) or not with metformin (17.680±6.644 ng/mL) (P=0.01). Multiple regression revealed that serum testosterone was not affected by the gene expression of the IGF-1 receptor or by BMI. CONCLUSIONS: the high serum concentrations of estradiol and testosterone and the larger number of oocytes in the group ofwomen with PCOS not treated with metformin lead us to conclude that women with PCOS probably have greater sensitivity to stimulation ofovarian steroidogenesis than women without the disease, although no difference was detected in the expression of the IGF-I receptor between the three groups studied. The similarity ofthe present results for the women with PCOS treated with metformin and for the women with ovulatory cycles leads us to hypothesize that one of the possible mechanisms of action of metformin on the IGF-1 system in cumulus granulosa cells may be of the post-receptor type.
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Rôle du facteur de croissance IGF-1 (Insulin-Like Growth Factor-1) sur le caractère souche du mélanome métastatique : vers une nouvelle cible thérapeutique contre la dissémination et la résistance aux traitements / Role of IGF-1 (Insulin-Like Growth Factor-1) in the Metastatic Melanoma Stem Character : Towards a New Therapeutic Target Against the Spread and Treatment ResistanceLe Coz, Vincent 14 October 2016 (has links)
Le mélanome métastatique représente le plus mortel des cancers cutanés par sa forte résistance aux thérapies conventionnelles. Les cellules initiatrices de tumeurs (CIT) sont présentes dans de nombreux cancers dont le mélanome. Ces cellules, capables de s’autorenouveller, sont à l’origine de la récidive tumorale et des métastases représentant une cible pour le développement de nouveaux traitements. Les CIT sont confinées dans un microenvironnement tumoral dans lequel des facteurs sécrétés tels que l'Insulin-Like Growth Factor-1 (IGF-1) et le Transforming growth factor (TGF-β) favorisent la transition épithéliomésenchymateuse (TEM), un processus clef lié à l’émergence des CIT. En utilisant des cellules de mélanome métastatique, nous avons montré qu’une inhibition d’IGF-1 induit une diminution de la tumorigénicité des cellules en diminuant la capacité des B16-F10 à former des métastases pulmonaires. Outre son action sur la prolifération cellulaire, IGF-1 est impliqué dans le processus de TEM favorisant les propriétés migratoires et invasives des cellules B16-F10. Par ailleurs, IGF-1 joue un rôle majeur dans le maintien des CIT expliquant la forte résistance des mélanomes aux thérapies conventionnelles. Des expériences préliminaires suggèrent que ces activités induites par IGF-1 pourraient être médiées en partie par le facteur TGF-β, un facteur clef de la TEM. D'autres résultats confortent cette hypothèse en montrant une implication directe du TGF-β dans le caractère souche des cellules B16-F10. Ces travaux montrent que l’inhibition de la voie IGF-1/IGF-1R dans le microenvironnement tumoral pourrait être une bonne stratégie pour le développement de traitements anti-tumoraux contre le mélanome. / Metastatic melanoma is arguably the most virulent among human cancers, owing to its propensity to metastasize, and its resistance to conventional therapies. Like in many other cancers, tumor stem cells or tumor initiating cells (TIC), have been identified in melanoma. These cells have the unique ability to self-sustain and renew the tumor and thus represent an interesting target for the development of new therapeutic strategies. TIC are nested in a confined microenvironment where secreted-factors such as Insulin-Like Growth Factor- 1 (IGF-1) and transforming growth factor (TGF-β) promote epithelialmesenchymal transition (EMT), a key process in stemness features acquisition. In this context, we investigated the effects IGF-1 on TIC behavior. Using B16-F10 metastatic melanoma cell line, we show that IGF-1 downregulation curbs lung metastasis suggesting that IGF-1 plays a direct role in the intrinsic tumorigenic potential of these cells.markers associated with an increased expression of the epithelial marker E-cadherin and of the major regulator of melanocyte differentiation MITF. Most importantly, IGF-1 inhibition sharply decreased stemness features, reducing the expression of key stem markers and functional characteristics of MIC. This was associated with an important sensitivity to mitoxantrone treatment. Interestingly, our preliminary data suggest the EMT key component, TGF-β, conveys IGF-1-mediated effects. Indeed, TGF-β directly affects B16-F10 stemness phenotype and markers. In summary, we show that the IGF-1/IGF-1R nexus represents an interesting target for the development of novel therapeutic strategies against metastatic melanoma.
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Rôle de la voie IGF-1 dans la sensibilité des plasmocytes tumoraux aux inhibiteurs du protéasome / The chemosensitivity of plasma cells to conventional treatments and the modulation of this sensivity by IGF-1 pathwayTagoug, Ines 17 December 2010 (has links)
Le myélome multiple (MM) est une hémopathie dont la croissance et la prolifération sont liés à une variété de facteurs de croissance, y compris « insulin-like growth factor type 1 » (IGF-1). Bortézomib est le premier inhibiteur protéasome ayant une activité anti-tumorale significative dans le myélome multiple. Nous avons analysé l'impact de l'IGF-1 recombinant associé à l'inhibiteur du protéasome bortezomib sur des lignées humaines de MM, in vivo et sur des cellules de myélome frais humaines ex vivo. Nous avons montré que l'IGF-1 améliore l'activité cytotoxique du bortezomib in vitro, in vivo et ex vivo. Nous avons montré que l'accroissement de la toxicité peut être inhibé par la présence d'un anticorps monoclonal dirigé contre le récepteur de l'IGF-1 (IGF1-R). IGF-1 renforce l'activité cytotoxique des autres inhibiteurs de protéasome, y compris MG115, MG132, PSI et epoxomicin. Nos résultats confirment le fait que l'IGF-1sensibilise des cellules de myélome à l'activité cytotoxique des inhibiteurs du protéasome tels que le bortezomib, en raison du niveau accru du stress de réticulum endoplasmique et l'induction de la une réponse protéine dépliée (UPR) / Multiple Myeloma (MM) is a clonal plasma cell disorder whose growth and proliferation are linked to a variety of growth factors, including insulin-like growth factor type 1 (IGF-1). Bortezomib, the first-in-class proteasome inhibitor, has displayed significant antitumor activity in multiple myeloma. We analyzed the impact of recombinant IGF-1 combined with the proteasome inhibitor bortezomib in MM cell lines, in vivo and on fresh human myeloma cells ex vivo. We found that IGF-1 enhanced the cytotoxic activity of bortezomib in vitro, in vivo and ex vivo. We showed that the enhanced toxicity could be inhibited by the presence of a monoclonal antibody directed against the IGF-1 receptor (IGF1-R). IGF-1 enhances the cytotoxic activity of other proteasome inhibitors, including MG115, MG132, PSI and epoxomicin. Our results support the fact that IGF-1sensitize myeloma cells to the cytotoxic activity of proteasome inhibitors such as bortezomib, as a consequence of enhanced level of endoplasmic reticulum stress and the induction of an unfolded protein response (UPR)
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Zusammenhang zwischen Geburtsverlauf und stoffwechselrelevanten Parametern bei Milchkühen und FärsenAbo Albanat, Waid 26 October 2016 (has links)
In der Nutztierhaltung besitzt die Erkennung und Vermeidung von Geburtsstörungen beim Rind insbesondere aus ökonomischer Sicht einen hohen Stellenwert. Bei Hochleistungskühen können Schwergeburten eine erhöhte metabolische Belastung im peripartalen Zeitraum reflektieren. Besonders betroffen sind Färsen und Milchkühe mit einer negativen Energiebilanz. Hormon- und Stoffwechselfaktoren sind von zentraler Bedeutung für die Anpassung der Tiere an Veränderungen ihrer Körpermasse und -konstitution. Zur differenzierten Beurteilung metabolischer Belastungen bei Hochleistungskühen im peripartalen Zeitraum wurden mögliche Zusammenhänge zwischen Geburtsverlauf und den stoffwechselrelevanten Parametern Leptin, Insulin-like growth factor-1 (IGF-1) und freien Fettsäuren (FFS) untersucht.
Die vorliegende Studie umfasste 28 adulte, hochträchtige (13 primipare, 15 pluripare) Kühe mit Normal- bzw. Schwergeburt. Die Kälber wurden analog zu ihren Müttern ebenfalls 4 Gruppen (Kuhkalb/Normalgeburt; Kuhkalb/Schwergeburt; Färsenkalb/Normalgeburt; Färsenkalb/Schwergeburt) zugeordnet. Die Analyse von Leptin, IGF-1 und FFS im Blutserum erfolgte zwischen dem 16./14. Tag ante partum (a. p.) und dem 14. Tag post partum (p. p.). Leptin und IGF-1 wurden zusätzlich bei den neugeborenen Kälbern ab der Geburt bis 14 Tage
p. p. gemessen. Die Hormonkonzentrationen wurden mittels eines Enzymimmunoassays bestimmt. Die FFS-Analysen erfolgten im Labor der Medizinischen Tierklinik mit dem Labor-Automaten HITACHI 912 i (Roche Diagnostics GmbH, Mannheim).
Unabhängig vom Geburtsverlauf konnten während des gesamten Untersuchungszeitraums bezüglich der Leptinkonzentrationen keine signifikanten Unterschiede zwischen Färsen und Milchkühen festgestellt werden. Vor allem zur Geburt besteht für alle Erstkalbinnen eine erhöhte metabolische Belastung, da deren IGF-1-Konzentrationen zu diesem Zeitpunkt niedriger (114 ± 40 vs. 158 ± 108 ng/ml) und deren FFS-Konzentrationen signifikant höher lagen (896 ± 273 vs. 705 ± 225 µmol/l, p = 0,05) als bei den Milchkühen. Im Vergleich zu den Kälbern von Milchkühen wiesen Kälber von Färsen 12 Stunden nach der Geburt signifikant höhere IGF-1-Werte (p = 0,05) auf.
In Abhängigkeit vom Geburtsverlauf lagen die Leptinwerte bei allen Kühen mit Schwergeburt von Beginn der Untersuchungen bis einen Tag vor der Geburt niedriger als bei den Tiere mit Normalgeburt mit signifikanten Unterschieden am 13. bis 11. Tag a. p. (p = 0,009) und am 7. bis 5. Tag a. p. (p = 0,05). Während des gesamten Untersuchungszeitraums waren keine signifikanten Unterschiede in den Konzentrationen an IGF-1 und FFS zwischen allen Muttertieren mit einem normalen und einem erschwerten Geburtsverlauf festzustellen.
Bei pluriparen Kühen mit Schwergeburt wurden im gesamten Untersuchungszeitraum niedrigere Leptinspiegel nachgewiesen als bei Tieren mit Normalgeburt, mit signifikanten Unterschieden a. p. und ab 3. Tag p. p. (p < 0,05 bzw. p < 0,01). Darüber hinaus fanden sich bei pluriparen Kühen mit Dystokie ab der Geburt höhere FFS-Konzentrationen mit signifikanten Unterschieden zur Kalbung (p = 0,05). Die Leptinkonzentrationen der Kälber lagen analog zu den dazugehörigen Muttertieren ab der Geburt bis 14. Tag p. p. bei allen Kälbern von pluriparen Kühen mit Schwergeburt niedriger als bei den normal geborenen Kälbern mit signifikanten Unterschieden am 7. Tag p. p. (p = 0,04).
Im Vergleich zu den Färsen mit Normalgeburt hatten diejenigen mit Schwergeburt signifikant höhere Leptinwerte vom 3. bis 14. Tag p. p. (p = 0,004), signifikant niedrigere IGF-1-Konzentrationen am 10. bis 8. Tag a. p., zur Geburt und vom 3. Tag bis 14. Tag p. p. (jeweils p < 0,01) sowie postpartal niedrigere FFS-Konzentrationen mit signifikanten Unterschieden 12 Stunden p. p. (p = 0,008). Kälber von Färsen mit gestörtem Geburtsverlauf wiesen im Vergleich zu den Normalgeburtskälbern 12 Stunden nach der Geburt signifikant niedrigere IGF-1-Werte (p = 0,005) auf.
Die vorliegende Studie verdeutlicht den Zusammenhang zwischen einem gestörten Geburtsablauf und veränderten Serumkonzentrationen an Leptin, IGF-1 und FFS. Damit konnte gezeigt werden, dass diese Parameter zur Interpretation von Stoffwechselstörungen bei Hochleistungskühen im peripartalen Zeitraum geeignet sind. / For livestock management, the identification and prevention of dystocia in cattle is of high significance, especially from an economic point of view. Dystocia in the high-yield cows may reflect an increased metabolic disorder during the peripartal period. Heifers and dairy cows with a negative energy balance are particularly affected. For the adaptation of animals to changes in their body mass and constitution, endocrine and metabolic factors are of central importance. To perform a differentiated assessment of metabolic disorders in high-yield cows during the peripartal period, possible relationships between calving and relevant parameters (leptin, insulin-like growth factor1 [IGF-1] and non-esterified fatty acids [NEFA]) were examined.
The present study involved 28 adult high-pregnant (13 primiparous, 15 pluriparous) cows with normal birth and dystocia, respectively. Analogous to their mothers, the calves were likewise categorized into four groups (cow calve/ normal birth; cow calve/ dystocia; heifer calve/ normal birth; heifer calve/ dystocia). The analyses of leptin, IGF-1 and NEFA in blood serum were performed from 16/14 day ante-partum (a. p.) to day 14 post-partum (p. p.). Leptin and IGF-1 were additionally determined in all newborn calves from birth to 14 days p. p. Hormone concentrations were measured by enzyme immunoassay (EIA). Analyses of NEFA in dairy cows and heifers were carried out using HITACHI 912i device (Roche Diagnostics GmbH, Mannheim) at the laboratory of Large Animal Clinic for Internal Medicine.
Independent of course of parturition, no significant differences between heifers and dairy cows were noticed concerning serum leptin during the entire examination period. Especially around calving time, all heifers were more intensively affected with metabolic disorders based on their lower IGF-1 values (114 ± 40 vs. 158 ± 108 ng/ml) as well as significantly higher NEFA (896 ± 273 vs. 705 ± 225 µmol/l, p = 0.05) compared to dairy cows. Calves of heifers had significantly higher IGF-1 values 12 hours after birth (p = 0.005) than calves of dairy cows.
Dependent of course of parturition, all cows with dystocia displayed lower leptin concentrations from the beginning of the examination period to 1 day a. p compared to animals with normal calving with significant differences from day 13 to day 11 a. p.
(p = 0.009) and from day 7 to day 5 a. p. (p = 0.05). During the entire examination period, no significant differences in the concentrations of IGF-1 and NEFA were found between all cows with a normal and difficult parturition.
In pluriparous cows with difficult parturition lower leptin levels were detected during the entire examination period than in animals with normal calving with significant differences a. p. and from day 3 to day 14 p. p. (p < 0.05 and p < 0.01, respectively). Furthermore, higher NEFA concentrations were found from birth until 14 days p. p. in pluriparous cows with dystocia and significant differences at calving (p = 0.05). Calves of pluriparous cows with dystocia had p. p. lower leptin concentrations in comparison to those with normal births with significant differences on day 7 p. p. (p = 0.04).
In comparison to heifers with normal birth, those with dystocia displayed significantly higher leptin levels in the period from day 3 to day 14 p. p. (p = 0.004), significantly lower IGF-1 concentrations (from day 10 to day 8 a. p., at birth and from day 3 to day 14 p. p.; each p < 0.01), as well as lower NEFA levels after birth with significant differences 12 hours p. p. (p = 0.008). Heifer calves with difficult parturition presented significantly lower IGF-1 values 12 hours p. p. (p = 0.005) in comparison to those with normal births.
The present study underlines the relationship between dystocia and changed serum concentrations of leptin, IGF-1 and NEFA. In summary, it can be concluded that these parameters are suitable for interpretation of metabolic disorders in high-yielding cattle during peripartal period.
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Zusammenhang zwischen Geburtsverlauf und stoffwechselrelevanten Parametern bei Milchkühen und FärsenAbo Albanat, Waid 01 November 2016 (has links) (PDF)
In der Nutztierhaltung besitzt die Erkennung und Vermeidung von Geburtsstörungen beim Rind insbesondere aus ökonomischer Sicht einen hohen Stellenwert. Bei Hochleistungskühen können Schwergeburten eine erhöhte metabolische Belastung im peripartalen Zeitraum reflektieren. Besonders betroffen sind Färsen und Milchkühe mit einer negativen Energiebilanz. Hormon- und Stoffwechselfaktoren sind von zentraler Bedeutung für die Anpassung der Tiere an Veränderungen ihrer Körpermasse und -konstitution. Zur differenzierten Beurteilung metabolischer Belastungen bei Hochleistungskühen im peripartalen Zeitraum wurden mögliche Zusammenhänge zwischen Geburtsverlauf und den stoffwechselrelevanten Parametern Leptin, Insulin-like growth factor-1 (IGF-1) und freien Fettsäuren (FFS) untersucht.
Die vorliegende Studie umfasste 28 adulte, hochträchtige (13 primipare, 15 pluripare) Kühe mit Normal- bzw. Schwergeburt. Die Kälber wurden analog zu ihren Müttern ebenfalls 4 Gruppen (Kuhkalb/Normalgeburt; Kuhkalb/Schwergeburt; Färsenkalb/Normalgeburt; Färsenkalb/Schwergeburt) zugeordnet. Die Analyse von Leptin, IGF-1 und FFS im Blutserum erfolgte zwischen dem 16./14. Tag ante partum (a. p.) und dem 14. Tag post partum (p. p.). Leptin und IGF-1 wurden zusätzlich bei den neugeborenen Kälbern ab der Geburt bis 14 Tage p. p. gemessen. Die Hormonkonzentrationen wurden mittels eines Enzymimmunoassays bestimmt. Die FFS-Analysen erfolgten im Labor der Medizinischen Tierklinik mit dem Labor-Automaten HITACHI 912 i (Roche Diagnostics GmbH, Mannheim).
Unabhängig vom Geburtsverlauf konnten während des gesamten Untersuchungszeitraums bezüglich der Leptinkonzentrationen keine signifikanten Unterschiede zwischen Färsen und Milchkühen festgestellt werden. Vor allem zur Geburt besteht für alle Erstkalbinnen eine erhöhte metabolische Belastung, da deren IGF-1-Konzentrationen zu diesem Zeitpunkt niedriger (114 ± 40 vs. 158 ± 108 ng/ml) und deren FFS-Konzentrationen signifikant höher lagen (896 ± 273 vs. 705 ± 225 µmol/l, p = 0,05) als bei den Milchkühen. Im Vergleich zu den Kälbern von Milchkühen wiesen Kälber von Färsen 12 Stunden nach der Geburt signifikant höhere IGF-1-Werte (p = 0,05) auf.
In Abhängigkeit vom Geburtsverlauf lagen die Leptinwerte bei allen Kühen mit Schwergeburt von Beginn der Untersuchungen bis einen Tag vor der Geburt niedriger als bei den Tiere mit Normalgeburt mit signifikanten Unterschieden am 13. bis 11. Tag a. p. (p = 0,009) und am 7. bis 5. Tag a. p. (p = 0,05). Während des gesamten Untersuchungszeitraums waren keine signifikanten Unterschiede in den Konzentrationen an IGF-1 und FFS zwischen allen Muttertieren mit einem normalen und einem erschwerten Geburtsverlauf festzustellen.
Bei pluriparen Kühen mit Schwergeburt wurden im gesamten Untersuchungszeitraum niedrigere Leptinspiegel nachgewiesen als bei Tieren mit Normalgeburt, mit signifikanten Unterschieden a. p. und ab 3. Tag p. p. (p < 0,05 bzw. p < 0,01). Darüber hinaus fanden sich bei pluriparen Kühen mit Dystokie ab der Geburt höhere FFS-Konzentrationen mit signifikanten Unterschieden zur Kalbung
(p = 0,05). Die Leptinkonzentrationen der Kälber lagen analog zu den dazugehörigen Muttertieren ab der Geburt bis 14. Tag p. p. bei allen Kälbern von pluriparen Kühen mit Schwergeburt niedriger als bei den normal geborenen Kälbern mit signifikanten Unterschieden am 7. Tag p. p. (p = 0,04).
Im Vergleich zu den Färsen mit Normalgeburt hatten diejenigen mit Schwergeburt signifikant höhere Leptinwerte vom 3. bis 14. Tag p. p.
(p = 0,004), signifikant niedrigere IGF-1-Konzentrationen am 10. bis 8. Tag a. p., zur Geburt und vom 3. Tag bis 14. Tag p. p. (jeweils p < 0,01) sowie postpartal niedrigere FFS-Konzentrationen mit signifikanten Unterschieden 12 Stunden p. p. (p = 0,008). Kälber von Färsen mit gestörtem Geburtsverlauf wiesen im Vergleich zu den Normalgeburts-kälbern 12 Stunden nach der Geburt signifikant niedrigere IGF-1-Werte (p = 0,005) auf.
Die vorliegende Studie verdeutlicht den Zusammenhang zwischen einem gestörten Geburtsablauf und veränderten Serumkonzentrationen an Leptin, IGF-1 und FFS. Damit konnte gezeigt werden, dass diese Parameter zur Interpretation von Stoff-wechselstörungen bei Hochleistungskühen im peripartalen Zeitraum geeignet sind. / For livestock management, the identification and prevention of dystocia in cattle is of high significance, especially from an economic point of view. Dystocia in the high-yield cows may reflect an increased metabolic disorder during the peripartal period. Heifers and dairy cows with a negative energy balance are particularly affected. For the adaptation of animals to changes in their body mass and constitution, endocrine and metabolic factors are of central importance. To perform a differentiated assessment of metabolic disorders in high-yield cows during the peripartal period, possible relationships between calving and relevant parameters (leptin, insulin-like growth factor1 [IGF-1] and non-esterified fatty acids [NEFA]) were examined.
The present study involved 28 adult high-pregnant (13 primiparous, 15 pluriparous) cows with normal birth and dystocia, respectively. Analogous to their mothers, the calves were likewise categorized into four groups (cow calve/ normal birth; cow calve/ dystocia; heifer calve/ normal birth; heifer calve/ dystocia). The analyses of leptin, IGF-1 and NEFA in blood serum were performed from 16/14 day ante-partum
(a. p.) to day 14 post-partum (p. p.). Leptin and IGF-1 were additionally determined in all newborn calves from birth to 14 days p. p. Hormone concentrations were measured by enzyme immunoassay (EIA). Analyses of NEFA in dairy cows and heifers were carried out using HITACHI 912i device (Roche Diagnostics GmbH, Mannheim) at the laboratory of Large Animal Clinic for Internal Medicine.
Independent of course of parturition, no significant differences between heifers and dairy cows were noticed concerning serum leptin during the entire examination period. Especially around calving time, all heifers were more intensively affected with metabolic disorders based on their lower IGF-1 values (114 ± 40 vs. 158 ± 108 ng/ml) as well as significantly higher NEFA (896 ± 273 vs. 705 ± 225 µmol/l, p = 0.05) compared to dairy cows. Calves of heifers had significantly higher IGF-1 values 12 hours after birth (p = 0.005) than calves of dairy cows.
Dependent of course of parturition, all cows with dystocia displayed lower leptin concentrations from the beginning of the examination period to 1 day a. p compared to animals with normal calving with significant differences from day 13 to day 11 a. p.
(p = 0.009) and from day 7 to day 5 a. p. (p = 0.05). During the entire examination period, no significant differences in the concentrations of IGF-1 and NEFA were found between all cows with a normal and difficult parturition.
In pluriparous cows with difficult parturition lower leptin levels were detected during the entire examination period than in animals with normal calving with significant differences a. p. and from day 3 to day 14 p. p. (p < 0.05 and p < 0.01, respectively). Furthermore, higher NEFA concentrations were found from birth until 14 days p. p. in pluriparous cows with dystocia and significant differences at calving (p = 0.05). Calves of pluriparous cows with dystocia had p. p. lower leptin concentrations in comparison to those with normal births with significant differences on day 7 p. p. (p = 0.04).
In comparison to heifers with normal birth, those with dystocia displayed significantly higher leptin levels in the period from day 3 to day 14 p. p. (p = 0.004), significantly lower IGF-1 concentrations (from day 10 to day 8 a. p., at birth and from day 3 to day 14 p. p.; each
p < 0.01), as well as lower NEFA levels after birth with significant differences 12 hours p. p. (p = 0.008). Heifer calves with difficult parturition presented significantly lower IGF-1 values 12 hours p. p.
(p = 0.005) in comparison to those with normal births.
The present study underlines the relationship between dystocia and changed serum concentrations of leptin, IGF-1 and NEFA. In summary, it can be concluded that these parameters are suitable for interpretation of metabolic disorders in high-yielding cattle during peripartal period.
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