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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

The Role of Luteal Phase Fallopian Tube Epithelium in High-grade Ovarian Serous Carcinoma

Tone, Alicia 05 September 2012 (has links)
Studies of prophylactic salpingectomy specimens from BRCA1/2 mutation carriers, at risk for tubal and ovarian high-grade serous carcinoma (SerCa), have consistently revealed occult carcinomas and putative histological cancer precursors in the distal fallopian tube epithelium (FTE), supporting the FTE as the source of SerCa. In this thesis I molecularly characterized and compared non-malignant FTE from mutation carriers (FTEb) and control patients (FTEn) to identify alterations that may predispose to malignant transformation. Gene expression profiling of laser capture microdissected FTEn, FTEb and SerCa indicated that SerCa have similar molecular profiles whether of presumed ovarian or tubal origin, supporting the notion they share a common cell of origin within the FTE. Furthermore, FTEb samples obtained during the post-ovulatory luteal phase showed gene expression profiles closely resembling SerCa samples, suggesting that the luteal phase milieu may contribute to serous carcinogenesis. An initial hypothesis was that FTEb may respond differently to luteal progesterone compared to FTEn, via differential expression of progesterone receptor (PR) isoforms. However, similar relative isoform expression in FTEn and FTEb samples suggested that a luteal phase-associated factor other than progesterone directs gene expression changes in FTEb. The possibility that FTEb respond differently to ovulation-associated inflammatory cytokines that are locally elevated during the luteal phase was next investigated. Importantly, FTEb specimens previously found to cluster with SerCa based on their global gene expression profiles showed evidence of increased nuclear factor-κB (NFκB)-dependent (pro-inflammatory) signalling and diminished glucocorticoid receptor (GR)-dependent (anti-inflammatory) signalling. Furthermore, I demonstrate that disabled homolog 2 (DAB2), an adaptor molecule decreased in SerCa and FTE luteal samples, enhances both GR-mediated transactivation and suppression of NFκB signalling, implicating DAB2 as a crucial determinant of inflammatory signalling and ovarian cancer risk. Altogether, this thesis identifies gene expression changes in FTE from BRCA mutation carriers during the post-ovulatory luteal phase that parallel those detected in SerCa. The data support a proposed novel testable model for predisposing events contributing to SerCa that centres on an altered ability to quickly resolve the pro-inflammatory environment created by the ovulatory event.
192

The interaction of environmentally relevant pollutants with nuclear hormone receptors of European flounder (Platichthys flesus)

Colliar, Louise January 2012 (has links)
Nuclear hormone receptors (NHRs) are ligand-activated transcriptions factors which transduce the effects of various hormones as well as nutritional and other environmental signals. They thus function to maintain physiological homeostasis by integrating the tissue expression of specific target genes to regulate a wealth of biological processes including reproduction, development, metabolism and environmental adaptation. Mounting evidence indicates NHRs are the target of endocrine disrupting compounds (EDCs), exogenous chemicals, often of anthropogenic origin, which disrupt NHRs and thus the processes under their control. EDCs can interfere with NHR signalling by activating receptors (agonists), by inhibiting the actions of the receptor (antagonists), or by disrupting endogenous hormone synthesis, secretion, transport or metabolism. Much of the focus to date has been on the risk of EDCs to reproductive functions, via estrogen and androgen NHRs in humans, and also in aquatic organisms. However environmental pollutants also have the potential to interact with other NHRs, particularly in aquatic environments, and cause dysregulation of other critical physiological processes, including energy homeostasis, immune functions and the stress response. To address this possibility a reporter gene assay was developed, allowing the high-throughput screening of pollutants for their interactions with piscine NHRs with critical roles in energy homeostasis, stress reponse and immune functions, namely the peroxisome proliferator-activated receptors (PPARs) and corticosteroid receptors (CRs) from European plaice (Pleuronectes platessa) and European flounder (Platichthys flesus), respectively. Complementary DNA (cDNA) sequences encoding the ligand-binding domains of PPARs and CRs, critical for receptor-ligand interactions and receptor activation, were ligated to the DNA-binding domain (DBD) of the yeast Gal4 transcription activator protein to create experimental expression plasmid constructs. Co-transfection of these expression plasmids into the fathead minnow (FHM) cell line with an upstream-activating sequence (UAS)-firefly luciferase reporter gene plasmid increased luciferase expression in the presence of known PPAR and CR ligands. Several aquatic pollutants including pharmaceuticals, industrial by-products and biocides were tested for their potential to disrupt PPAR and CR functions by interacting with these receptors in an agonistic or antagonistic manner. Several fibrates, a group of pharmaceutical compounds used to treat dyslipidemia in humans by targeting the PPARs, were able to activate plaice Gal4-PPARα and Gal4-PPARβ in the reporter gene assay, indicative of an interaction with PPAR receptors in non-target species. Fibrates which did not activate Gal4-PPARα were able to inhibit the activation of Gal4-PPARα by the PPARα-specific agonist, Wy14643, suggesting differential effects of fibrates on human and flounder PPARs. In addition some metabolites of widespread phthalate ester pollutants were also agonists of the Gal4-PPARα and Gal4-PPARβ constructs. The Gal4-PPARγ construct was unresponsive to almost all the compounds tested, including the mammalian PPARγ agonist, rosiglitazone. The exception to this was the phthalate metabolite monobenzylphthalate, which induced a small increase in firefly luciferase in Gal4-PPARγ transfected cells. All of the above effects required concentrations of at least 10 µM, which are unlikely to be encountered in the aquatic environment. In contrast bis(tributyltin) oxide (TBTO), a notorious environmental pollutant, inhibited Gal4-PPARα and Gal4-CR constructs at concentrations as low as 1 nM and 100 nM, respectively. These concentrations are lower than those reported in aquatic environments, or in fish tissues, making TBTO a candidate endocrine disruptor in fish by inhibiting PPARα and CR signalling. A European flounder cDNA microarray was used to investigate the trasnscriptional responses of flounder hepatocytes to TBTO (10 nM) exposure. Exposure to TBTO and Wy14643, both alone and in combination, indicated a TBTO-driven downregulation of several potential PPARα-target genes with functions in the immune system, the proteasome, and lipid metabolism, although, based on mammalian comparisons, some potential PPARα-target genes were also upregulated, indicating differences in mammalian and fish PPAR-target genes or reflecting the complexity of organisms at a higher organisational level than cell-based assay systems. However, the microarray-based approach was useful in formulating further hypotheses about the effects of TBTO on PPARα signalling. Overall, these results indicate that exogenous chemicals entering the aquatic environment can interfere with NHRs with functions in energy homeostasis, immune functions and stress, in non-target organisms. The cell-based reporter gene assay is a useful tool for identifying potential endocrine disruptors which target PPARs and CRs and would be a useful method in a first tier testing approach, limiting the use of live animal models and enabling investigation into specific receptors which are targets of endocrine disrupting compounds. Although more work is required to confirm the physiological consequences of TBTO inhibition of PPARα, the results presented here indicate that organisms inhabiting TBTO-polluted environments may experience suppression of the immune system, an increase in non-functional or misfolded proteins through suppression of genes involved in the ubiquitin/proteasome system and a disruption in lipid homeostasis.
193

Glucocorticoid receptor signalling and the effect of interleukin 1 beta on glucocorticoid mediated gene expression in intestinal epithelial cell lines Caco-2 and IEC-6

Toth, Szilvia 31 October 2000 (has links)
No description available.
194

CHARACTERIZING CONSUMPTION, DEPENDENCE, AND THE ROLE OF GLUCOCORTICOIDS IN AN ANIMAL MODEL OF VOLUNTARY ETHANOL CONSUMPTION

Sharrett-Field, Lynda 01 January 2013 (has links)
Alcohol abuse disorders (AUD) represent a serious worldwide health problem with far reaching social, financial, and interpersonal implications. One of the most devastating facets of these disorders is the propensity to relapse following periods of abstinence. Ethanol withdrawal (EWD) is believed to promote relapse by increasing anxiety and craving, and may contribute to the development of cognitive decline associated with long-term dependence. Clinical data suggest that stress also plays a main role in both the development of AUD as well as relapse to drinking. As a physiological stressor, EtOH elevates levels of stress hormones (cortisol in humans, corticosterone (CORT) in the rat). Both CORT and EtOH have been shown to alter the composition, function, and activity of the N-methyl-D-aspartate (NMDA) receptor, and in particular, the NR2B subunit of this receptor. These alterations have been suggested to mediate EWD, which may negatively impact abstinence rates. This synergistic interaction between EtOH and CORT may present a therapeutic target for the treatment of EWD. In fact, data suggest that blocking the glucocorticoid receptor, which is a main target for CORT, with RU-486 could promote abstinence, as treatment with the drug has been shown to reduce consumption and the development dependence, as well as the severity of EWD and the cognitive deficits following EWD. However, these latter effects have not been validated in models of voluntary EtOH consumption. As there is considerable evidence that active versus passive intake can significantly impact neuroadaptations to ethanol this is an important consideration. These studies sought to characterize consumption and evaluate the development of dependence in a chronic voluntary model of intermittent access (IA) to EtOH. CORT plasma levels and protein expression of the glucocorticoid and NR2B receptors were measured during and/or following exposure. Finally, to assess the role of CORT in EtOH consumption and the development of dependence, the glucocorticoid receptor antagonist ORG-34517 was administered during access to EtOH. IA access to 20% EtOH produced varying levels of consumption (2.0-6.7g/kg/24hr exposure) and blood EtOH levels (6.3-116.9 mg/dl), but did not significantly affect food consumption or weight gain. Baseline CORT levels were found to be predictive of subsequent EtOH consumption and levels of consumption were sufficient to elevate CORT levels following one hour of EtOH exposure. Further, IA to EtOH was sufficient to produce dependence, as measured by elevations in the acoustic startle reflex following 26 hours and five days of withdrawal. No alteration in protein expression was observed regarding either the NR2B or glucocorticoid receptors and exposure to ORG-34517 had no effect on consumption or withdrawal.
195

Late-Onset Triple A Syndrome: A Risk of Overlooked or Delayed Diagnosis and Management

Salmaggi, Andrea, Zirilli, Lucia, Pantaleoni, Chiara, De Joanna, Gabriella, Del Sorbo, Francesca, Köhler, Katrin, Krumbholz, Manuela, Hübner, Angela, Rochira, Vincenzo 19 February 2014 (has links) (PDF)
Background/Aims: A 33-year-old man was referred for the first time to the Division of Neurology because of the presence and progression of neurological symptoms. Dysphagia, weakness, reduced tear production, and nasal speech were present. In order to point the attention of late-onset triple A syndrome we describe this case and review the literature. Methods: Hormonal and biochemical evaluation, Schirmer test, tilt test and genetic testing for AAAS gene mutations. Results: Late-onset triple A syndrome caused by a novel homozygous missense mutation in the AAAS gene (A167V in exon 6) was diagnosed at least 17 years after symptom onset. Conclusions: The association between typical signs and symptoms of triple A syndrome should suggest the diagnosis even if they manifest in adulthood. The diagnosis should be confirmed by Schirmer test, endocrine testing (both basal and dynamic), genetic analysis, and detailed gastroenterological and neurological evaluations. Awareness of the possible late onset of the disease and of diagnosis in adulthood is still poor among clinicians, the acquaintance with the disease is more common among pediatricians. The importance of an adequate multidisciplinary clinical approach, dynamic testing for early diagnosis of adrenal insufficiency and periodical reassessment of adrenal function are emphasized. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
196

Glucocorticoid receptor cross-talk with NF-kappaB and AP-1 : functional role and mechanisms /

Bladh, Lars-Göran, January 2005 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 4 uppsatser.
197

Modulation of folate receptor-[alpha] by glucocorticoid receptor and progesterone receptor

Tran, Thuyet Van. January 2004 (has links)
Thesis (Ph. D.)--Medical College of Ohio, 2004. / "In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Medical Sciences." Major advisor: Manohar Ratnam. Includes abstract. Document formatted into pages: iii, 293 p. Title from title page of PDF document. Includes bibliographical references (p. 175-281).
198

Efeito do polimorfismo A3669G do gene do receptor de glicocorticoide sobre o controle metabólico, comportamento alimentar e neuroimagem funcional em uma amostra de adolescentes

Rodrigues, Danitsa Marcos January 2015 (has links)
Introdução: Os glicocorticoides (GCs) estão envolvidos na regulação e adaptação da resposta ao estresse, exercendo seus efeitos através de seus receptores. Variações polimórficas no gene do receptor de glicocorticoide (GR) têm sido caracterizadas funcionalmente. O polimorfismo A3669G do gene do GR está relacionado a modificações na sensibilidade aos GCs e mudanças no perfil metabólico. Concentrações fisiológicas de GCs estimulam a ingestão calórica e, na presença de insulina, modificam a preferência alimentar. A variante A3669G do gene do GR parece levar a um menor risco para diabetes, em pacientes com Síndrome de Cushing, e para o tabagismo, quando associado a um polimorfismo do gene do receptor de mineralocorticoide, sugerindo uma modulação na via de recompensa. O objetivo deste trabalho é avaliar a associação de variantes do polimorfismo A3669G do gene do GR com o comportamento alimentar e parâmetros metabólicos em uma amostra de estudantes, correlacionando com dados de neuroimagem funcional. Métodos: A amostra provém de alunos de 6 escolas de Porto Alegre, avaliados em 2008 e em 2013. Em 2008, 131 indivíduos apresentavam o protocolo completo de avaliação e, destes, 74 retornaram em 2013. A avaliação incluiu genotipagem, antropometria, exames laboratoriais, comportamento alimentar e um paradigma avaliando a ativação cerebral em resposta a visualização de imagens de alimentos palatáveis, não palatáveis e de objetos neutros. A análise da associação com os fenótipos foi realizada através do teste t de Student e Chi quadrado; os dados do estudo longitudinal foram analisados por meio de Equações de Estimatição Generalizada. Resultados: A variante G do polimorfismo A3669G do gene do GR foi encontrado em 17,6% em 2008 e em 14,9% da amostra em 2013. Não houve diferença entre os grupos de carreadores do alelo G e não carreadores quanto a diferentes confundidores; a comparação entre as médias dos dois grupos sobre o consumo calórico proveniente de proteínas, carboidratos e gorduras em 2008 não revelou diferenças significativas; nesta etapa, as análises evidenciaram maior consumo de açúcares e de calorias totais no grupo não carreador do alelo G. Em 2013, estes indivíduos não carreadores do alelo G do polimorfismo A3669G apresentaram maior insulinemia e além de aumento no índice de resistência à insulina, sem diferenças no consumo alimentar. Os dados de neuroimagem funcional indicaram que a visualização de imagens de alimentos palatáveis pelo grupo não carreador do alelo G ativou o giro occipital médio, uma região implicada no processamento visual, mostrando menor ativação em giro pré central e nas áreas de Brodmann 4 e 6, relacionadas ao planejamento motor e sensibilidade ao sabor. Conclusão: Os resultados mostram que os indivíduos não carreadores da variante G do polimorfismo A3669G do gene do GR apresentaram menor sensibilidade à insulina, precedidos pela modulação na preferência alimentar. Os achados em neuroimagem funcional indicam maior saliência de incentivo aos alimentos palatáveis e predisposição à impulsividade no grupo não carreador do alelo G. Sugere-se que a redução na sensibilidade em nível celular aos GCs relacionada à presença do alelo G, afete a ingestão alimentar, reduzindo o consumo de alimentos palatáveis, diminuindo o risco para doenças metabólicas. / Introduction: Glucocorticoids are involved in regulation and adaptation of the stress response, exerting effects through its receptors. Variations on the glucocorticoid receptors genes have been characterized functionally. The A3669G polymorphism of the glucocorticoid receptor gene is related to a change in the tissue sensitivity to glucocorticoids and altered metabolic profile. Physiological concentrations of glucocorticoids stimulate food intake and in the presence of insulin affect food preferences. The G variant of the A3669G polymorphism appears to lead to a lower risk for diabetes, in patients with Cushing's syndrome, and smoking, when associated with a polymorphism of the mineralocorticoid receptor gene, suggesting a modulation in reward pathways. The objective of this study is to evaluate the association of A3669G polymorphism variants with feeding behavior and metabolic parameters in a sample of students correlating with functional neuroimaging data. Methods: The sample includes students of 6 schools in Porto Alegre, evaluated at two occasions 2008 and in 2013. In 2008, 131 individuals had complete protocol assessment and, from these, 74 returned in for re- evaluation in 2013. The evaluation included genotyping, anthropometry, laboratory tests, feeding behavior and a functional MRI paradigm to verify brain activation in response to the visualization of palatable, non- palatable foods and neutral items. The association with phenotypes was performed using Student's t test and Chi-square; longitudinal study data were evaluated using Generalized Estimating Equations. Results: The variant of the A3669G polymorphism was found in 17.6% of the students in 2008 and 14.9% of the sample in 2013. There was no difference between groups in the sample composition; the comparison between groups of the mean caloric intake originating from proteins, carbohydrates and fats in 2008 revealed no significant differences; at this time, analysis showed lower consumption of sugars and total calories in the G carrier group. In 2013, these individuals showed a reduction in insulin level and resistance, with no differences in food intake. The fMRI data indicated that viewing a food palatable image by the wild-type allele carrier group activated a region involved in visual processing (middle occipital gyrus) and deactivated an area related to motor planning and sensitivity to taste (pre central gyrus). Conclusion: The results showed that G carriers of the A3669G polymorphism of glucocorticoid receptor gene had lower insulin resistance levels, preceded by modulation of their food preference. The findings in functional neuroimaging showed increased incentive salience on viewing palatable food images and a predisposition for impulsivity in noncarriers. Data suggest that reduction in glucocorticoids sensitivity at a cellular level affects food intake, by reducing consumption of palatable foods, possibly decreasing the risk for metabolic diseases.
199

Efeito da privação de sono paradoxal na expressão de receptores para glicocorticoides no hipocampo e no aprendizado e memória / Effect of paradoxical sleep deprivation in Expression of glucocorticoid receptors in hippocampus and learning and memory

Paulo Cesar da Costa Araujo 29 February 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Vários trabalhos têm demonstrado uma relação entre sono e memória. Desta forma, tem sido descrito um papel importante do sono na consolidação da memória e um efeito negativo pela privação do mesmo. O hipocampo é uma região importante para a formação e consolidação da memória espacial, e contém uma alta expressão de receptores para corticosteróides. As ações dos corticosteróides no hipocampo são fundamentais para a aquisição de memória e dependem de um balanço adequado entre receptores de Glicocorticóides (RGc) e Mineralocorticóides (RMn). Assim é descrito na literatura que um aumento na expressão de RMn é promotor de aquisição de memória, enquanto que um aumento na expressão de RGc produz um efeito negativo. Apesar dos níveis circulantes de glicocorticóides na privação de sono paradoxal (PSP), não serem responsáveis pelo enfraquecimento de memória, não existem dados sobre a expressão dos receptores para corticosteróides no hipocampo, após PSP. Neste trabalho tivemos como objetivo investigar a expressão de receptores de Glicocorticóides no hipocampo, bem como avaliar aprendizado e memória em ratos privados de sono paradoxal. Ratos Wistar machos (250- 350g) foram submetidos à PSP, utilizando-se o método de múltiplas plataformas por um período de 96 horas. Após 96h de privação os animais foram anestesiados e perfundidos. Secções de 25 μm na área do hipocampo foram obtidas e reagidas com anticorpos para receptores de Glicocortidóides. Avaliamos as áreas CA1, CA3 e Giro Denteado. O aprendizado e memória espacial foram avaliados através do teste do labirinto aquático de oito braços, antes e após o período de privação de sono. Avaliou-se a latência de escape e o número de erros obtidos. O grupo PSP apresentou um aumento na expressão de RGc nas regiões: CA1 e Giro Denteado, não se observando diferença significativa na região CA3. A PSP prévia aos testes de aprendizado e memória não provocou alterações significativas. A privação de sono pós-aprendizado também não produziu diferenças estatisticamente significativas, mas um aumento no tempo de latência de escape e número de erros sugere um enfraquecimento na consolidação da memória. O aumento na expressão de RGc nas áreas estudadas, pode ser consequente a uma alteração no balanço entre os receptores para corticosteróides no hipocampo e ser responsável por alterações no aprendizado e memória em ratos PSP. / Several studies have shown a relation between sleep and memory. In this way, an important role in memory consolidation by sleep and a negative effect induced by sleep deprivation have been described. Hippocampus is a region responsible for consolidation of spatial memory and contains a high expression of corticosteroids receptors. In the hippocampus, the corticosteroids actions are crucial for memory acquisition and depend on an adequate balance between Glucocorticoid (GR) and Mineralocorticoid receptors (MR). Studies have demonstrated that an increased expression of MR promotes memory acquisition while an increased expression of GR has negatives effects. In spite of the circulating levels of glucocorticoids in paradoxical sleep deprivation (PSD) are not responsible for the PSD induced memory impairments, do not exist studies about the expression of the GR and MR in hippocampus after PSD. In this study we investigate the expression of GR in the hippocampus and evaluate learning and memory in PSD rats. Wistar male rats (250-350g) were paradoxical sleep deprived by the multiple platform method for 96 hours. After 96h of sleep deprivation, the animals were anesthetized and perfused. Slices of 25 micron of the area of the hippocampus were obtained and reacted with antibodies against GR. We evaluated the areas CA1, CA3 and dentate gyrus (GD). Learning and spatial memory were evaluated in Radial water maze before and after PSD. We evaluated the escape latency and the number of errors obtained. PSD group showed an increased expression of GR in CA1 and GD. However, in the CA3 area there was no significant difference in expression. The PSD prior to the tests of learning and memory did not provoke significant alterations. The sleep deprivation after learning also did not produce statistically significant differences, but an increase in the time of escape latency and number of errors suggests impairment in the memory consolidation. The increase in the RGc expression in the studied areas can be consequent to an alteration in the balance between corticosteroid receptors in the hippocampus and be responsible for alterations in the learning and memory in PSD rats.
200

Efeito da privação de sono paradoxal na expressão de receptores para glicocorticoides no hipocampo e no aprendizado e memória / Effect of paradoxical sleep deprivation in Expression of glucocorticoid receptors in hippocampus and learning and memory

Paulo Cesar da Costa Araujo 29 February 2012 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Vários trabalhos têm demonstrado uma relação entre sono e memória. Desta forma, tem sido descrito um papel importante do sono na consolidação da memória e um efeito negativo pela privação do mesmo. O hipocampo é uma região importante para a formação e consolidação da memória espacial, e contém uma alta expressão de receptores para corticosteróides. As ações dos corticosteróides no hipocampo são fundamentais para a aquisição de memória e dependem de um balanço adequado entre receptores de Glicocorticóides (RGc) e Mineralocorticóides (RMn). Assim é descrito na literatura que um aumento na expressão de RMn é promotor de aquisição de memória, enquanto que um aumento na expressão de RGc produz um efeito negativo. Apesar dos níveis circulantes de glicocorticóides na privação de sono paradoxal (PSP), não serem responsáveis pelo enfraquecimento de memória, não existem dados sobre a expressão dos receptores para corticosteróides no hipocampo, após PSP. Neste trabalho tivemos como objetivo investigar a expressão de receptores de Glicocorticóides no hipocampo, bem como avaliar aprendizado e memória em ratos privados de sono paradoxal. Ratos Wistar machos (250- 350g) foram submetidos à PSP, utilizando-se o método de múltiplas plataformas por um período de 96 horas. Após 96h de privação os animais foram anestesiados e perfundidos. Secções de 25 μm na área do hipocampo foram obtidas e reagidas com anticorpos para receptores de Glicocortidóides. Avaliamos as áreas CA1, CA3 e Giro Denteado. O aprendizado e memória espacial foram avaliados através do teste do labirinto aquático de oito braços, antes e após o período de privação de sono. Avaliou-se a latência de escape e o número de erros obtidos. O grupo PSP apresentou um aumento na expressão de RGc nas regiões: CA1 e Giro Denteado, não se observando diferença significativa na região CA3. A PSP prévia aos testes de aprendizado e memória não provocou alterações significativas. A privação de sono pós-aprendizado também não produziu diferenças estatisticamente significativas, mas um aumento no tempo de latência de escape e número de erros sugere um enfraquecimento na consolidação da memória. O aumento na expressão de RGc nas áreas estudadas, pode ser consequente a uma alteração no balanço entre os receptores para corticosteróides no hipocampo e ser responsável por alterações no aprendizado e memória em ratos PSP. / Several studies have shown a relation between sleep and memory. In this way, an important role in memory consolidation by sleep and a negative effect induced by sleep deprivation have been described. Hippocampus is a region responsible for consolidation of spatial memory and contains a high expression of corticosteroids receptors. In the hippocampus, the corticosteroids actions are crucial for memory acquisition and depend on an adequate balance between Glucocorticoid (GR) and Mineralocorticoid receptors (MR). Studies have demonstrated that an increased expression of MR promotes memory acquisition while an increased expression of GR has negatives effects. In spite of the circulating levels of glucocorticoids in paradoxical sleep deprivation (PSD) are not responsible for the PSD induced memory impairments, do not exist studies about the expression of the GR and MR in hippocampus after PSD. In this study we investigate the expression of GR in the hippocampus and evaluate learning and memory in PSD rats. Wistar male rats (250-350g) were paradoxical sleep deprived by the multiple platform method for 96 hours. After 96h of sleep deprivation, the animals were anesthetized and perfused. Slices of 25 micron of the area of the hippocampus were obtained and reacted with antibodies against GR. We evaluated the areas CA1, CA3 and dentate gyrus (GD). Learning and spatial memory were evaluated in Radial water maze before and after PSD. We evaluated the escape latency and the number of errors obtained. PSD group showed an increased expression of GR in CA1 and GD. However, in the CA3 area there was no significant difference in expression. The PSD prior to the tests of learning and memory did not provoke significant alterations. The sleep deprivation after learning also did not produce statistically significant differences, but an increase in the time of escape latency and number of errors suggests impairment in the memory consolidation. The increase in the RGc expression in the studied areas can be consequent to an alteration in the balance between corticosteroid receptors in the hippocampus and be responsible for alterations in the learning and memory in PSD rats.

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