O objetivo deste trabalho foi avaliar, em ratos, os efeitos do consumo, em curto prazo, de dieta hiperlipídica e deficiente em magnésio (Mg) na adiposidade, no status de Mg, na sensibilidade à insulina, e no status inflamatório e oxidativo. Foi inicialmente realizado um ensaio piloto (n = 12), de 24 dias, que permitiu avaliar o padrão alimentar dos animais. A dieta hiperlipídica testada teve sua composição em micronutrientes aumentada proporcionalmente à redução esperada de consumo. A partir desses resultados, delineou-se o ensaio principal, de 32 dias, com os animais alimentados com rações controle (ad libitum [CT; n = 8] e pair-feeding [PF; n = 16]), e hiperlipídica (adequada [HF; n = 12] e deficiente em Mg [HFMg-; n = 12]). Foram avaliados a adiposidade, o perfil lipídico, o status de Mg, a resistência insulínica (glicemia e insulinemia de jejum, teste de tolerância à insulina - TTI, fosforilação do receptor de insulina [IR-β], do substrato 1 do IR [IRS-1] e da proteína quinase B [Akt]), e marcadores de inflamação e de estresse oxidativo. O consumo de dieta HFMg- e HF resultou em maior ganho de peso e adiposidade em relação ao PF. Da mesma forma os grupos HF e HFMg- apresentaram concentrações séricas de colesterol total, VLDL-c e de triacilgliceróis mais elevadas em relação ao grupo PF. Como esperado, os animais HFMg- apresentaram alterações no status de Mg, evidenciadas pela redução de suas concentrações no osso e na urina. Apesar de não terem sido observadas diferenças na glicemia e na insulinemia entre os grupos, a menor fosforilação das proteínas da via de sinalização de insulina comprovam que a deficiência de Mg agrava os efeitos da dieta hiperlipídica nesta via. Não foram observadas diferenças nos parâmetros de inflamação e de estresse oxidativo. No entanto, observou-se associação inversa do malondialdeído e do inibidor do ativador de plasminogênio-1 com o status de Mg. Os resultados do presente estudo reforçam a importância da análise de micronutrientes em dietas experimentais, a fim de se obter dados reprodutíveis. A utilização do grupo PF permitiu verificar que o consumo de dietas hiperlipídicas predispõem a maior adiposidade, resistência insulínica e dislipidemia, e que a deficiência de Mg pode piorar a resistência insulínica. / The aim of this study was to assess, in rats, the effects of high-fat and magnesium (Mg) deficient diet, in short-time, on adiposity, magnesium status, insulin sensitivity, and oxidative and inflammatory status. Firstly, it was realized a pilot study (n = 12), 24 days, which allowed to assess the dietary patterns of the animals. The high-fat diet tested had its micronutrient composition increased proportionally to the expected reduction in consumption. Based in these results, it was outlined the principal study, 32 days, with the animals fed with control diet (ad libitum [CT; n = 8] and pair-feeding [PF; n = 16]), and high-fat diet (adequate [HF; n = 12] and magnesium deficient [HFMg-; n = 12]). It was assessed the adiposity, serum lipid profile, Mg status, insulin resistance (fasting glucose and insulin, insulin tolerance test - ITT, phosphorylation of insulin receptor [IR-β], insulin receptor substrate 1 [IRS-1] and protein kinase B [Akt]), and markers of inflammation and oxidative stress. The consumption of HFMg- and HF results in greater weight gain and adiposity compared to PF. Likewise, the high-fat groups showed serum total cholesterol, VLDL-c, and triglycerides higher than PF group. As expected, the animals showed changes in magnesium status, as evidenced by lower bone and urine levels. Although no differences were observed in blood glucose and serum insulin levels among the groups, the lowest phosphorylation of the insulin signaling pathway show that Mg deficiency intensifies the effects of high-fat diet in this pathway. No differences were observed in the inflammatory and oxidative stress parameters. However, it was observed an inverse association of malondialdehyde and plasminogen activator inhibitor-1 with Mg status. The results of this study support the importance of micronutrients analyzes in the experimental diets, in order to obtain reproducible data. With the PF group it was showed that high-fat diets predisposes to greater adiposity, dyslipidemia, insulin resistance, and that Mg deficiency can worse the effects on insulin resistance.

O objetivo deste trabalho foi de avaliar em Modelo animal, coelhos (raça Nova Zelândia) divididos em três grupos randomizados, (jovem com 60 dias (G1), um idoso com aterosclerose e ingestão de colesterol (G2) e um idoso com aterosclerose e sem ingestão do colesterol (G3)) se, a dieta rica em colesterol e a idade, causam lesões de aterosclerose e placas ateroscleróticas nos animais, alterações nos comprimentos dos dentes, aumento ou diminuição dos espaços periapicais dos dentes, perda óssea alveolar na maxila e mandíbula. Através da metodologia descrita e após as análises histológicas e morfológicas, verificou-se diferença estatisticamente significante, nas variáveis dos comprimentos dos dentes 1º prémolares superiores entre os grupos G3 versus G1 p<5%. médias de 1247,88 (p=0,017) e G3 versus G2, com diferença das médias de 1190,85 (p=0,025) ou seja o comprimento dos dentes fora diferente no grupo G2. Com relação à variável, espessura do osso alveolar, não ocorreu significância estatística, porém tendências de que este esteja sendo alterado. Com relação a variável espessura do espaço periapical fora verificado significância estatística com p=0,017 em relação ao G1, na região dos 1º Pré-molares, apresentando a diferença das médias (403,42) a favor do G2, ou seja aumento do espaço periapical. A variável da área de placa de aterosclerose, correlacionada, com os comprimentos dos dentes e espessura do osso alveolar, também teve resultado significante na região 1º e 2º pré-molares entre G2 e G3. com p=0,025 e r=0,476. Confirmando assim a correlação da aterosclerose, dietas hiperclesterolêmicas e as alterações da cavidade bucal e estrutura de sustentação dos dentes. / The aim of this study is, to evaluate on animal model (New Zealand rabbits), on different and randomized groups (G1 a young group, G2 an older rabbit, with atherosclerosis and ingesting hipercholesterolemic fat diet and another group G3, just an older group) investigated than the hipercholesterolemic fat diet induced atherosclerotic lesions and plaques in ascendant aorta, bone loss in maxillary and jaw, alterations on length of the tooth, alterations on tooth periapical spaces. By the methodology described and aplicated, before the histological and morphological analysis, was verified significant statistical variance in the length of the first premolar tooth and second premolar on maxillary region, the length of this tooth is reduced in G2 (p<5%). The medias are 1247,88 (p=0,017) and 1190,85 (p=0,025). Analyzing another variable on the alveolar bone thickness, was not found any statistical significance, but tendencies that this event may occur. According to another variable of the thickness found on the periapical space, it was verified a significant variable statistic such as p=0,017 related on G1, on first premolar region, suggesting a different statistic, between medias, favoring G2 meaning the increase of periapical space. The variable on the atherosclerosis plaque area, related to the teeth length and alveolar bone thickness, also showed significant results on first and second premolars regions between G2 and G3, with p=0,025 and r=0,476. That confirms the atherosclerosis correlations and hipercholestrolemic fat diet, also alterations in oral cavity and teeth implantation structure.

Orientadores: Henrique Marques Barbosa de Souza, Carla Beatriz Collares Buzato / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-25T12:54:45Z (GMT). No. of bitstreams: 1 Hernandes_LeticiaHelenaPinto_M.pdf: 22200442 bytes, checksum: 95e81ba6b7934db5b7e01d5eea75202c (MD5) Previous issue date: 2014 / Resumo: O Diabetes Mellitus tipo 2 (T2DM) representa uma das principais doenças do mundo moderno, e é caracterizado pelo comprometimento da homeostase glicêmica do organismo, resultante de uma combinação da redução da sensibilidade periférica à insulina e o comprometimento da função das células-'beta'. Estudos recentes sugerem que Coup-TFII possui um papel importante na homeostase glicêmica e no metabolismo energético. Apesar destes trabalhos representarem fortes indícios, ainda é desconhecido se Coup-TFII desempenharia este papel modulador da homeostase glicêmica e do metabolismo energético em indivíduos com T2DM. O objetivo deste trabalho foi investigar o padrão de expressão de Coup-TFII em camundongos apresentando um quadro pré-diabético. Para isto, foram utilizados camundongos C57BL/6 tipo selvagem tratados com dieta hiperlipídica (dHL) por 60 dias (animais dHL). A caracterização metabólica revelou que estes animais apresentaram características de quadro pré-diabético, i.e., sobrepeso, resistência periférica à insulina associada à moderada hiperglicemia, significativa hiperinsulinemia (resultante da hiperplasia compensatória de células-'beta') e distúrbios na secreção de insulina, tanto no estado basal (2,8 mM de glicose), quanto em condição estimulatória (16,8 mM de glicose). A análise da expressão de Coup-TFII por qPCR revelou uma redução dos níveis transcricionais deste gene em ilhotas dos animais dHL. Estes resultados indicam que a relação negativa previamente demonstrada entre hiperglicemia, hiperinsulinemia e reduzida secreção de insulina e a expressão de Coup-TFII também ocorre no quadro pré-diabético desenvolvido pelos animais dHL. Interessantemente, análise do conteúdo proteico de Coup-TFII revelou um aumento significativo de 33,6% nos animais dHL, resultado que contrasta com a redução da transcrição deste gene nas células-'beta' destes animais. Uma possível explicação seria pelo papel fundamental que Coup-TFII exerce no processo de proliferação das células-'beta' dependente da via Wnt/'beta'-catenina, observada durante o desenvolvimento e potencialmente atuando na hiperplasia compensatória nos animais dHL. Além disso, trabalhos recentes demonstraram que Coup-TFII atua como um regulador negativo de sua própria transcrição em células-'beta'. Portanto, com 60 dias de tratamento o quadro de hiperplasia nos animais dHL demandaria maiores níveis da proteína de Coup-TFII em comparação com os animais Ctr. Uma vez elevado, este nível proteico de Coup-TFII, juntamente com os efeitos das alterações metabólicas, teriam um efeito negativo sobre a transcrição de Coup-TFII nos animais dHL / Abstract: Type 2 diabetes mellitus (T2DM) is one of the most important diseases in the modern world, and is characterized by the compromise of the glycemic homeostasis and a result of a combination of insulin resistance and impaired 'beta'-cell function. Recent studies show that nuclear receptor COUP- TFII (Chicken ovalbumim upstream promoter transcription factor II) plays an important role in regulating glycemic homeostasis and energy metabolism. Although these results are a strong hint, it is still unknown whether Coup-TFII would have a role modulating glycemic homeostasis and energy metabolism in individuals suffering from T2DM. The aim of this work was to investigate the expression pattern of the transcription factor Coup-TFII in mice displaying pre-diabetic condition. To this aim, C57BL/6, wildtype mice were treated with high fat diet (dHL, from the Portuguese dieta hiper lipídida) for 60 days (dHL mice). Metabolic characterization confirmed that dHL mice display characteristics of pre-diabetic condition, i.e., overweigh, insulin resistance associated with moderate hyperglycemia, hyperinsulinemia (as a result of hyperplasia of 'beta'-cells) and impaired insulin secretion both, in basal and high blood glucose concentrations. Gene expression analysis for Coup-TFII by qPCR revealed a significant reduction of its transcripts in pancreatic islet of dHL animals. These results indicate that the previously described negative relationship between hyperglycemia, hyperinsulinemia and imparted insulin secretion and Coup-TFII expression is also happening in the pre-diabetic condition developed by dHL animals. Interestingly, analysis of the protein expression of Coup-TFII reveled a significant increase of 33,6% in dHL animals, a result that the contrasts with the reduction of Coup-TFII transcripts observed in these animals. One possible explanation is the essential role that Coup-TFII plays in the Wnt/'beta'-catenin-dependent 'beta'-cell proliferation, in addition to the negative feedback loop observed in 'beta'-cells for Coup-TFII on its own expression. By 60 days of treatment, 'beta'-cell proliferation during hyperplasia in dHL animals would require levels of Coup-TFII protein higher then in control animals. Once increased, this higher protein level, in addition to the metabolic alterations, would have a negative effect on Coup-TFII transcription in dHL animals / Mestrado / Biologia Celular / Mestre em Biologia Celular e Estrutural

Orientadores: Sebastião Roberto Taboga, Silvana Gisele Pegorin de Campos / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-23T14:53:15Z (GMT). No. of bitstreams: 1 Goncalves_BiancaFacchim_D.pdf: 8580892 bytes, checksum: 1e3927b5ad73e189b4b4245aa141895e (MD5) Previous issue date: 2013 / Resumo: Um dos principais desafios no campo de pesquisa do câncer prostático é a busca por sistemas modelo que permitam a investigação dos aspectos patológicos, bioquímicos e genéticos desta doença. O gerbilo Meriones unguiculatus tem possibilitado a avaliação de lesões prostáticas e sua evolução de estágio benigno para maligno (invasivo) após período relativamente curto de tratamento com o carcinógeno N-Metil-N-Nitrosuréia (MNU), um potente causador de metilação do DNA por ação direta. Assim, o presente trabalho teve por objetivos: 1) Determinar a incidência, multiplicidade e latência tumoral de lesões espontâneas e quimicamente induzidas nos lobos prostáticos ventral e dorsolateral do gerbilo; 2) Investigar se o estradiol exerce papel protetor e/ou promotor sobre neoplasias induzidas por MNU; 3) Avaliar o potencial promotor da dieta hiperlipídica sobre a carcinogênese induzida na próstata ventral; 4) Analisar a participação de produtos alterados de genes ras e do status global de metilação do DNA do epitélio prostático no processo tumoral mediado por MNU. Para tanto foram utilizados animais adultos submetidos à dose única intraperitoneal de MNU (50mg/Kg), exceto o grupo controle. Os grupos experimentais foram submetidos à exposição crônica de andrógeno, estradiol ou dieta hiperlipídica por 14 e 28 semanas. As metodologias aplicadas envolveram análises quantitativas e estatísticas de multiplicidade e incidência de lesões prostáticas, peso corporal, acúmulo de gordura corporal, peso prostático, dosagens hormonais, índice proliferativo, cariometria, frequência de células AR-positivas e basais, status global de metilação e determinação da expressão de proteínas. O modelo de indução tumoral prostática por MNU associado à testosterona no gerbilo se mostrou eficaz, pois reduziu a latência tumoral e permitiu o estudo de estágios avançados da carcinogênese após curto período. As neoplasias se manifestam inicialmente no lobo dorsolateral e requerem um tempo maior para se estabelecer no lobo ventral. No entanto, a progressão de lesões pré-malignas para malignas ocorre de maneira mais significativa no lobo ventral. Isso indica que a progressão tumoral ocorre de maneira distinta entre os lobos prostáticos e que vias alternativas estão possivelmente envolvidas nesse processo. A longa exposição a altas doses de estrógeno foi capaz de prevenir e reduzir a taxa de crescimento tumoral. Apesar dos efeitos terapêuticos contra a progressão neoplásica, a terapia estrogênica levou ao estabelecimento de um epitélio com características distintas da próstata normal, como: mudanças no padrão de metilação do DNA e aumento de células basais e AR positivas. Juntos, esses eventos contribuíram para criar um ambiente epitelial instável que pode provocar a recidiva das lesões em períodos subsequentes. A associação entre MNU e dieta hiperlipídica promoveu aumento na incidência de lesões estimuladas pelo carcinógeno isoladamente, as quais apresentaram maior número de células AR-positivas, ruptura da camada de músculo liso indicando microinvasão tumoral, e alta reatividade para metaloproteinase do tipo 2. A análise molecular indicou alta expressão das proteínas Ras em tecidos induzidos por MNU, sugerindo a participação dessa via na promoção e progressão de tumores prostáticos. Assim, conclui-se que a dieta hiperlipídica pode ser considerada um agente promotor da carcinogênese prostática, e o gerbilo representa um bom modelo para estudos histopatológicos / Abstract: One of the major challenges in the field of prostate cancer research is the search for model systems that allow the investigation of pathological, biochemical and genetic factors of this disease. The gerbil Meriones unguiculatus has enabled the evaluation of prostate lesions and evolution from benign to malignant (invasive) stage after a relatively short period of treatment with the carcinogen N-methyl-N-nitrosourea (MNU), a potent causative of DNA methylation by direct action. Thus, this study aimed to: 1) Determine the incidence, multiplicity, and tumor latency of spontaneous and chemically-induced lesions in ventral and dorsolateral gerbils' prostatic lobes; 2) Investigate whether estradiol exerts protective and/or promoter hole on neoplasms induced by MNU; 3) Evaluate the promotional potential of high-fat diet on induced-carcinogenesis in ventral prostate; 4) Analyze the involvement of altered ras gene products and the global DNA methylation status of prostate epithelium on MNU-mediated tumor process. Therefore, we used adult animals subjected to a single intraperitoneal dose (50mg/kg) of MNU, except the control group. The experimental groups were subjected to chronic exposure of androgen, estradiol or high-fat diet for 14 and 28 weeks. The methodologies involved quantitative and statistical analysis of multiplicity and incidence of prostatic lesions, body weight, body fat accumulation, prostate weight, hormonal measurements, proliferative index, karyometry, frequency of AR-positive and basal cells, global methylation status and determination of protein expression. The model of prostatic tumor induction by MNU associated with testosterone in the gerbil was effective because it reduced tumor latency and allows the study of advanced stages of carcinogenesis after short period. Neoplasms manifest initially in dorsolateral lobe and require a longer time to be established in ventral lobe. However, the progression from premalignant to malignant lesions occurs more significantly in the ventral lobe. This indicates that tumor progression occurs differently between prostatic lobes and alternative pathways maybe possibly involved in this process. Long exposure to high doses of estrogen was able to prevent and reduce the rate of tumor growth. Despite therapeutic effects against neoplastic progression, estrogen therapy led to the establishment of an epithelium with distinct characteristics from normal prostate, such as changes in the pattern of DNA methylation and increased amount of basal cell and ARpositive cells. Together, these events contributed to create an unstable epithelial compartment that can cause lesions recurrence in subsequent periods. The association between MNU and high-fat diet promoted an increase in incidence of lesions stimulated by carcinogen alone, which had a higher number of AR-positive cells, disruption of the smooth muscle layer indicating tumor microinvasion and high reactivity for metalloproteinase type 2. Molecular analysis indicated high expression of Ras proteins in tissues induced by MNU, suggesting the involvement of this pathway in the promotion and progression of prostate tumors. Thus, we conclude that the high-fat diet can be considered a promotional agent of prostate carcinogenesis and that gerbil is a good model for histopathological studies / Doutorado / Biologia Celular / Doutora em Biologia Celular e Estrutural

O risco aumentado de mortalidade e morbidade associado à obesidade tem sido alvo de muitos estudos que tentam elucidar os aspectos da Síndrome Metabólica, caracterizada por algumas doenças metabólicas como resistência à insulina, hipertensão, dislipidemia. Apesar de muitos estudos tentarem elucidar as alterações metabólicas decorrentes da obesidade, poucos trabalhos têm analisado as conseqüências da dieta hiperlipídica sobre o metabolismo de aminoácidos. Assim, o objetivo deste estudo foi verificar os possíveis mecanismos responsáveis pelo desenvolvimento da intolerância à glicose após a ingestão de dieta hiperlipídica em ratas saudáveis. Os animais alimentados com dieta hiperlipídica por 60 dias, apresentaram redução na expressão gênica de Glut 4 do receptor de insulina, além de redução na atividade da hexoquinase e aumento na atividade de citrato sintase, aspartato aminotransferase e BCAA transaminase, indicando adaptação nas vias metabólicas, com aumento da atividade do ciclo de Krebs e maior utilização de aminoácidos em reações anapleróticas. / The possible causes of increased mortality and morbidity associated with obesity have been focused by many studies that attempt to understand the metabolic syndrome, characterized by various metabolic disorders such as insulin resistance, hypertension and dyslipidemia. Thus, the aim of this study was to verify the possible mechanisms responsible for developing glucose intolerance after a high fat diet intake in healthy female rats. Female Wistar rats were fed either with high fat diet or with the control diet for several weeks. The rats fed with a high fat diet for 60 days presented impaired Glut 4 and insulin receptor gene expression. High fat diet promoted a reduced activity of hexokinase and increased activity of citrate synthase, aspartate aminotransferase and BCAA transaminase, indicating an adaptation in the metabolic pathway, with increase activity of Krebs cycle and increased usage of amino acids in anaplerotic reactions.

Obesity is tightly connected with metabolic diseases including insulin resistance, type 2 diabetes or dyslipidemia. Peroxisome proliferator-activated receptor (PPAR)-α is a key transcription factor involved in the regulation of lipid metabolism, while its activity is stimulated by a variety of hypolipidemic drugs. n-3 polyunsaturated fatty acids (PUFA), including eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid, are endogenous ligands of PPARα, and they are used in the form of fish oil as dietary supplements in order to lower blood lipid levels and to prevent cardiovascular disease. Wax esters represent a novel lipid form of EPA and DHA, and according to recent studies they could exert more potent effects than the classical fish oil (i.e. triacylglycerols). Mice of the 129S1/SvImJ inbred strain were used in the present experiment, and included wild-type (WT) mice, as well as transgenic mice either with the exclusive expression of the human form of PPARα (hPPARα) or mice completely lacking PPARα (PPARα-KO). Mice were fed for 8 weeks the following diets: (i) a control low-fat diet, (ii) obesogenic high-fat diet (cHF), and (iii) the cHF diet supplemented with the n-3 PUFA concentrate in the form of wax esters isolated from marine zooplankton Calanus finmarchicus (ω3Cal). Mice were subjected to...

Magister Scientiae (Medical Bioscience) - MSc(MBS) / Conclusion of this study: These data suggest that 6 weeks of high-fat feeding induces hypertension but does not produce obesity, dyslipidemia and insulin resistance. However, this model may be useful in studying vascular reactivity in hypertension in the absence of insulin resistance. / South Africa

Magister Scientiae (Medical Bioscience) - MSc(MBS) / Background: It is well known that some genetic factors and dietary factors, such as excessive salt intake and excessive caloric intake (resulting in obesity) are risk factors for hypertension. Fifty percent of all hypertensive patients are also insulin resistant. Both hypertension and insulin resistance are again risk factors for other cardiovascular diseases such as atherosclerosis and heart failure. The nature of the association between hypertension and insulin resistance has not been clearly elucidated. Spontaneously hypertensive rats are the ideal models to study the aspects of the relationships between hypertension and insulin resistance. Models of high-fat feeding induce obesity,hypertension and insulin resistance and are thus used extensively to study hypertension because these models closely mimic some of the renal and cardiovascular changes found in human hypertensive patients. The present study was initiated to evaluate if insulin resistance will develop within 6 weeks in a model of high-fat diet induced hypertension and if so, to determine whether captopril will affect the presence of insulin resistance.This model should in future be used to study vascular reactivity to phenylephrine (PHE),acetylcholine (ACH) and sodium nitroprusside (SNP) in hypertensive animals in theabsence or presence of insulin resistance and in normotensive insulin resistant animals. Methods: In a series of experiments, rats were divided into four groups that received different treatments: (i) laboratory pellets, (ii) high-fat diet, (iii) high-fat diet plus captopril and (iv) high-fat diet plus vehicle. Body weight was measured weekly for 6 weeks. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured every week during the 6-weeks feeding period by the tail cuff method using a two channel computerized non-invasive system from Kent Scientific Corporation, USA.m Intraperitonealy glucose tolerance tests (IPGTTs) were performed at week 3 and week 6.After 6 weeks, and after an overnight fast, the plasma lipid profile was determined using a portable CardiochekTM blood test system. Fasting plasma insulin was determined using an immunoenzymatic assay for the in vitro quantitative measurement of rat insulin (INS) in serum and plasma. Insulin sensitivity was estimated by the quantitative insulin sensitivity check index (QUICKI) using the fasting plasma insulin and fasting glucose levels. After week 6 on the high-fat diet, thoracic aortae from the control and high-fat fed(HFD) animals were excised and vascular response to PHE, ACH and SNP were assessed in intact and denuded endothelium.Result: High-fat feeding did not cause a significant increase in body weight. High-fat feeding significantly increased systolic blood pressure from 125±2.1 mmHg in control animals to 155±5.9 mmHg in the HFD group (P < 0.05) and 158±5.6 mmHg in the HFDV group (P < 0.05). Diastolic blood pressure was increased from 86±2.8 mmHg in the control group to 117±2.5 mmHg in the HFD group (P < 0.05) and 113±3.4 mmHg in the HFDV group (P < 0.05). Visceral fat was increased from 0.8±0.1g in the control group to 3.1±0.6 g in the HFD group and 3.8±0.6 g in the HFDV group. IPGTTs performed at weeks 3 and 6 respectively did not differ significantly from the control group as evidenced from the AUC’s at weeks 3 and 6 respectively. High-fat feeding had no significant effects on blood cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) values or and fasting plasma insulin levels. The KCl induced contraction in both aortic rings with intact and denuded endothelium did not differ significantly between the control and HFD groups (P= 0.4 and 0.8) respectively. The contraction mediated by KCl in aortic rings with intact and denuded endothelium from the control or HFD groups also did not differ significantly(control: intact vs denuded, P = 0.2; HFD: intact vs denuded, P = 1). Dose responsecurves(1-10 μM) to PHE indicated slightly stronger contractions in the high-fat fed animals at submaximal doses tested. The maximum contraction achieved was however the same (94±19% and 99±2.6% relative to KCl induced contraction, in the control and HFD group respectively, P<0.05). Relaxation responses to ACH and SNP represent preliminary data.Conclusion: These data suggest that 6 weeks of high-fat feeding induces hypertension but does not produce obesity, dyslipidemia and insulin resistance. However, this model may be useful in studying vascular reactivity in hypertension in the absence of insulin resistance.

Dans ce travail nous nous sommes intéressés à caractériser les modulateurs génétiques et environnementaux de la génération de thrombine (ETP).Nous avons montré que le taux d’antithrombine (AT) peut être considéré comme un facteur continu de risque de thrombose. L’ETP, le plus élevé, est observé chez les porteurs d’un déficit quantitatif en AT. Les porteurs de la mutation AT Cambridge II présentent également une augmentation de l’ETP. Parallèlement à l’AT, nous avons confirmé l’effet positif de l’allèle PT 20210A sur la génération de thrombine d’autant plus qu’il existe des antécédents personnels de thrombose veineuse (TV). A côté de ces contributions, nous avons confirmé le rôle des taux plasmatiques de fibrinogène et de facteur II, du groupe sanguin et de la prise de contraceptifs oraux sur l’ETP.Nos résultats montrent également que chez le rat, un régime riche en graisses a un effet sur la génération de thrombine. Le régime gras maintient des taux élevés d’ETP après le sevrage, alors qu’une alimentation standard le diminue. Cet effet est partiellement expliqué par l’élévation des taux de facteur VII coagulant et ne suit pas l’évolution des modifications classiques du métabolisme glucidolipidique. Les niveaux élevés d’ETP observés pendant une alimentation riche en graisses se normalisent quatre semaines après le retour à une alimentation standard.En conclusion nos données suggèrent que l’ETP peut être considéré comme un indicateur de l’état prothrombotique des patients, mais son utilisation à l’échelle individuelle dans la prédiction du risque de thrombose veineuse reste à approfondir. La mesure de la génération de thrombine peut être un outil utile pour évaluer les conséquences des modifications du régime alimentaire ou des médicaments pour traiter l’obésité sur le potentiel procoagulant circulant / In this work, we studied genetic and environmental modulators of thrombin generation by endogenous thrombin potential (ETP).We showed that plasma levels of antithrombin (AT) can be considered as risk factors for thrombosis. ETP levels are higher in patients presenting a quantitative defect of AT. In addition, mutation AT Cambridge II is also associated with an increase of ETP. Besides the AT, we confirmed a positive effect of the prothrombin 20210A allele on thrombin generation, especially in presence of venous thrombosis antecedents. These contributions, we have confirmed the role of plasma fibrinogen and factor II, blood group and oral contraceptives on thrombin generation.In addition, our results also showed an effect of high fat diet on thrombin generation in rats. Conversely to the standard fat diet, high fat diet maintened high levels of ETP after weaning. High fat diet-induced effects persisted four weeks after switching to standard fat diet. This effect could be partially explained by higher rates of coagulation factors VII and did not follow classical changes in glucidolipidic metabolism.In conclusion our data suggest that ETP can be considered as an indicator of the prothrombotic state in patients, but require more explanation to predict a risk of venous thrombosis. The measurement of thrombin generation may be a useful tool for assessing the impact of changes in diet or medication to treat obesity on circulating procoagulant potential.

Camundongos Swiss, quando submetidos à dieta hiperlipídica (HL), apresentam considerável ganho ponderal e de depósitos adiposos, tornando-se obesos e resistentes à insulina. O objetivo deste trabalho foi avaliar o efeito da dieta HL por 8 semanas no perfil inflamatório, síntese de triacilglicerol (TAG) com ênfase na vias de geração de glicerol-3-fosfato (G3P) e lipólise nos tecidos adiposos brancos (TAB) retroperitoneal (RETRO) e epididimal (EPI) de camundongos. Camundongos Swiss foram alimentados com as dietas: controle (CT) - dieta purificada (AIN-93G); ou HL - dieta AIN-93G modificada contendo 35% de lipídeos (4% de óleo de soja e 31% de gordura suína). Os camundongos alimentados com a dieta HL apresentaram uma maior massa corporal, acompanhada pelo aumento nos tecidos RETRO e EPI, além de desenvolverem resistência à insulina constatada no teste de tolerância à glicose (TTG), hiperglicemia e hiperinsulinemia. O conteúdo protéico da pAKT, avaliado por western blot (WB), e a adiponectina, dosada em homogenados dos tecidos adiposos, estão reduzidos apenas no EPI. Houve aumento na expressão gênica de MCP-1 e PAI-1, e foi observada menor área dos adipócitos no EPI, sem alteração no RETRO dos animais HL. A síntese de novo de ácidos graxos (AG), avaliada pela incorporação de 3H de 3H2O em AG foi maior em ambos os TAB, porém a captação de AG das lipoproteínas circulantes avaliada pela atividade e expressão da lipase lipoproteica (LPL) aumentou no EPI e reduziu no RETRO. A dieta HL induziu aumento na fosforilação do glicerol, avaliada pela atividade e conteúdo da GK que aumentaram nos dois TAB, e maior incorporação de 1-14C-glicerol em TAG no EPI. A captação de glicose in vitro e conteúdo do GLUT- 4, que indicam atividade da via glicolítica foram reduzidos no EPI e RETRO, assim como a gliceroneogênese avaliada pela incorporação de 1-14C-piruvato em TAG, sem alterações na atividade e conteúdo da fosfoenolpiruvato carboxiquinase (PEPCK). A atividade lipolítica basal foi avaliada in vitro pela liberação de glicerol por adipócitos isolados, e não foi alterada pela ingestão de dieta HL, porém quando estimulada por noradrenalina a liberação de glicerol foi menor nos animais HL, assim como as fosforilações da ATGL e HSL e conteúdo do receptor adrenérgico ?3. A dieta HL levou a uma redução no conteúdo de PPAR? e aumento de ATF3 em ambos os tecidos. No EPI houve aumento de pCREB, pSTAT3 e RGS2 em relação aos controles enquanto no RETRO a única diferença encontrada foi a menor pSTAT3. Nossos resultados demonstram que o aumento nos TAB é resultado de maior síntese e captação de AG, e que o G3P necessário para a esterificação a TAG é proveniente principalmente da fosforilação direta do glicerol pela GK; além disso, a reduzida lipólise também parece contribuir para esse quadro. Nos animais HL, o EPI parece ser mais propenso aos efeitos da dieta do que o RETRO / Swiss mice when subjected to high fat diet (HFD), shown considerable weight gain and adipose depots, becoming obese and insulin resistant. The aim of this study was to evaluate the effect of HFD diet for 8 weeks in the inflammatory profile, triacylglycerol (TAG) synthesis with emphasis in glycerol-3-phosphate (G3P) generation pathways and lipolysis in retroperitoneal (RETRO) and epididymal (EPI) white adipose tissue (WAT) of mice. Swiss mice were fed with diets: control (CT) - purified diet (AIN-93G); or HFD - purified diet (AIN-93G) plus 35% of fat (4% soybean oil and 31% of lard). Mice fed a HFD diet had a higher body mass, accompanied by an increase in RETRO and EPI tissues, in addition to developing insulin resistance, evidenced by glucose tolerance test (GTT), hyperglycemia and hyperinsulinemia. The protein content of pAKT, accessed by western blot, and adiponectin, measured in WAT homogenates, are reduced only in EPI. There was an increase in gene expression of MCP-1 and PAI-1, and was observed smaller area of adipocytes in EPI, with no change in RETRO of HFD fed animals. De novo synthesis of fatty acids (FA), evaluated by incorporation of 3H from 3H2O in FA was higher in both TAB, but the uptake of FA, from blood lipoproteins, evaluated by the activity and expression of lipoprotein lipase (LPL) was increased in EPI and reduced in RETRO. HFD induced increase in phosphorylation of glycerol, evaluated by the activity and content of glycerolkinase (GyK) which increased in both TAB and greater incorporation of 1-14C-glycerol in the TAG only in EPI. The in vitro glucose uptake and GLUT-4 content, which indicates the activity of the glycolytic pathway were reduced in EPI and RETRO, as well as glyceroneogenesis assessed by the incorporation of 1-14C- pyruvate into TAG without changes in the activity and contents of phosphoenolpyruvate carboxykinase (PEPCK). The basal lipolytic activity was evaluated in vitro by glycerol releasing from isolated adipocytes, and was not altered by HFD intake, but when stimulated by noradrenaline glycerol release was lower in HFD animals as well as the phosphorylation of ATGL and HSL and ?3 adrenergic receptor content. HFD led to a reduction in the content of PPAR gamma and an increase in ATF3 in both tissues. In EPI there was an increase in pCREB, pSTAT3 and RGS2 while in RETRO the only difference was reduced pSTAT3. Our results shown that TAB increase is result of increased FA synthesis and uptake, and G3P required for esterification TAG comes mainly from direct phosphorylation of glycerol by GyK; Furthermore, reduced lipolysis also seems to contribute to this scenario. HFD effects seem to be more prominent in EPI than in RETRO