• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 85
  • 53
  • 14
  • 13
  • 12
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 205
  • 129
  • 121
  • 113
  • 57
  • 37
  • 28
  • 26
  • 22
  • 21
  • 18
  • 18
  • 17
  • 16
  • 16
  • 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.
131

Neurodevelopmental Liabilities in Schizophrenia and Affective Disorders

Palomo, T., Kostrzewa, R. M., Archer, T., Beninger, R. J. 01 January 2002 (has links)
There is now considerable evidence that both schizophrenia and affective disorders have their origin at least in part in events that occur during early pre- and post-natal development. In the case of schizophrenia, many observations, for example, increased risk for schizophrenia in the offspring of mothers who had influenza A during their second trimester of pregnancy and evidence for abnormal neuronal migration in the cerebral cortex of post mortem tissue from schizophrenic patients, suggest that a second trimester insult may have occurred and that this insult may have increased the risk for the development of schizophrenia in late adolescence or early adulthood. Animal studies have found that rats that undergo excitotxic damage to the ventral hippocampus on postnatal day 7 develop exaggerated sensitivity to dopamine-stimulating drugs or to stressful stimuli that becomes apparent after sexual maturity but not before, providing a neurodevelopmental model of schizophrenia. Similarly, post-weaning social isolation leads to nehanced responses to dopaminergic drgus and to stress that emerges after sexual maturity. These animal models are proving to be valuable tools to study the neurobiological mechanisms mediating the influence of early insults to the nervous system on later behavioural functins. In the case of affective disorders, although the evidence is not as strong, a number of the same observations have been made suggesting that an insult during early ontogeny may lead to the development of affective disorders later in life. For example, retrospective studies of people with affective disorders showed that they were more likely to have attained motor milestones at a later age and to have had poorer academic performance as children. There is a wealth of evidence suggesting hyperfunctioning of the hypothalamic-pituitary-adrenal (HPA) axis in affective disorders. Animal studies have shown that early matenal deprivation can lead to lasting changes in the reactivity of the HPA axis to stressful stimuli, providing another link from early experience to adult psychopathology. Continued studies of the effects of pre- and early post-natal events on the development of the nervous system and the relationships of these events to schizophrenia or affective disorder will provide new insights into the mechanisms underlying these common neuropsychiatric illnesses.
132

Social Buffering By Unfamiliar Adult Males in Periadolescent Guinea Pigs: The Effects on HPA Axis Activity And Fos Induction In The Medial Prefrontal Cortex

Bertke, Alexander 04 June 2019 (has links)
No description available.
133

Microdialysis in the study of GABA and other putative amino acid neurotransmitters in the dorsomedial hypothalamus

Anderson, Jeffrey Joseph January 1990 (has links)
This document only includes an excerpt of the corresponding thesis or dissertation. To request a digital scan of the full text, please contact the Ruth Lilly Medical Library's Interlibrary Loan Department (rlmlill@iu.edu).
134

Factors Determining the Effects of Human Interaction on the Cortisol Levels of Shelter Dogs

Willen, Regina M. January 2015 (has links)
No description available.
135

EFFECT OF GUT PEPTIDES ON HYPOTHALAMIC mRNA CONCENTRATION AND DRY MATTER INTAKE IN RUMINANTS

Relling, Alejandro Enrique 22 July 2009 (has links)
No description available.
136

Repetitive stressors at various lifetime periods differentially affect the HPA axis, neuronal neurotrophic factors and behavioural responses

Faure, Jacqueline J 03 1900 (has links)
Thesis (MSc (Physiological Sciences))--University of Stellenbosch, 2006. / Early adverse life events appear to increase the susceptibility of developing psychiatric disorders later in life. The molecular mechanisms involved in the development of pathological behaviour remain unclear. Dysregulation of the hypothalamic-pituitary-adrenal axis and alterations in neurotrophic factors have been implicated.
137

ETHANOL REGULATION OF GLUCOCORTICOID RESPONSIVE GENES

Costin, Blair 18 April 2013 (has links)
Glucocorticoid hormones modulate acute and chronic behavioral and molecular responses to drugs of abuse including psychostimulants and opioids. Acute ethanol activates the hypothalamic pituitary adrenal (HPA) axis causing the release of adrenal glucocorticoid hormones, but following chronic ethanol the HPA axis is dysregulated in both humans and rodents. Thus, there is growing evidence that glucocorticoids might also modulate behavioral and molecular responses to ethanol. Previous microarray studies in the Miles’ laboratory have shown that the well-known glucocorticoid responsive gene, Serum and Glucocorticoid-regulated Kinase 1, Sgk1, is prominently up regulated by acute ethanol (2 g/kg) in the prefrontal cortex (PFC) of DBA/2J mice. Functionally, Sgk1 is an important focal point of intracellular signaling cross-talk through which the cell surface receptors, nuclear receptors, and cellular stress pathways converge to control many cellular processes including receptor or ion channel trafficking, cell proliferation and/or apoptotic responses. In the aforementioned microarray studies, Sgk1 was accompanied by a highly correlated group of genes, many of which are also known to respond to glucocorticoids. This suggests that stress-related signaling events might play an important role in ethanol regulation of the Sgk1 gene network. Prior work by others showed that Sgk1 plays an important role modulating synaptic plasticity occurring in memory. Based on these findings, it is hypothesized that glucocorticoids and glucocorticoid responsive genes are responsible for modulating acute and chronic cellular and behavioral responses to ethanol including locomotor activation and ethanol sensitization. In particular, because Sgk1 is regulated by ethanol, has a well-established role in learning and memory and is responsive to glucocorticoid signaling we hypothesize that Sgk1 is involved in modulating acute and chronic cellular and behavioral responses to ethanol including ethanol sensitization. Our results indicate that the induction of glucocorticoid responsive genes may play a role in regulating acute behavioral and cellular responses to ethanol. Adrenalectomized (ADX) and mifepristone (RU-486) both impaired acute ethanol (2 g/kg) induced locomotor activation in DBA/2J mice without affecting basal locomotor activity. ADX mice showed microarray gene expression changes in the PFC that significantly overlapped with acute ethanol-responsive gene sets derived by our prior microarray studies. Additionally, acute ethanol regulates Sgk1 transcription via glucocorticoid receptor binding to the Sgk1 promoter. Furthermore, increases in Sgk1 may occur to compensate for decreases in SGK1 protein and phosphorylation of SGK1 and its well-known target N-myc downstream-regulated gene 1 (NDRG1) is significantly increased 15 minutes following ethanol administration. Finally, Sgk1 intensifies and prolongs the expression phase of sensitization in D2 mice. Our studies suggest that ethanol’s activation of adrenal glucocorticoid release and subsequent glucocorticoid receptor activation may partially modulate ethanol’s acute locomotor activation in male D2 mice. Furthermore, adrenal glucocorticoid basal tone regulates PFC gene expression. A significant set of acute ethanol-responsive genes are regulated by adrenal glucocorticoid basal tone suggesting that glucocorticoid regulated PFC gene expression may be an important factor modulating acute behavioral responses to ethanol. Sgk1 is acutely regulated following ethanol administration by the glucocorticoid receptor binding to the Sgk1 promoter. Altogether, these results suggest a critical role for the hypothalamic pituitary adrenal axis and Sgk1 in regulating the acute and chronic cellular and behavioral responses to ethanol.
138

Estresse precoce e alterações do eixo hipotálamo-pituitária-adrenal (HPA) na depressão. / Early Life Stress and alterations of the Hypothalamic-Pituitary-Adrenal (HPA) axis in depression.

Baes, Cristiane von Werne 30 March 2012 (has links)
Introdução: Diversos estudos sugerem que o estresse nas fases iniciais de desenvolvimento pode induzir alterações persistentes na capacidade do eixo Hipotálamo-Pituitária-Adrenal (HPA) em responder ao estresse na vida adulta. O desequilíbrio do cortisol tem sido identificado como um correlato biológico dos transtornos depressivos. Essas anormalidades parecem estar relacionadas às mudanças na capacidade dos glicocorticóides circulantes em exercer seu feedback negativo na secreção dos hormônios do eixo HPA por meio da ligação aos receptores mineralocorticóides (RM) e glicocorticóides (RG) nos tecidos do eixo HPA. Devido à grande variedade de estressores, assim como os diferentes subtipos de depressão, os achados dos estudos atuais têm sido inconsistentes. Dessa forma, necessitando de mais estudos para que se possa elucidar os mecanismos envolvidos na associação entre o Estresse Precoce (EP) e o desenvolvimento de quadros depressivos. Objetivo: O objetivo deste estudo é avaliar a correlação entre Estresse Precoce e alterações no eixo Hipotálamo-Pituitária-Adrenal e na função dos receptores glicocorticóides e mineralocorticóides em pacientes depressivos. Metodologia: Foram recrutados inicialmente 30 sujeitos divididos em dois grupos: grupo de pacientes com diagnóstico de episódio depressivo atual (n=20) e grupo de controles (n=10). Posteriormente os pacientes foram divididos em outros dois grupos de acordo com o EP, compondo a amostra final por três grupos: grupo de pacientes depressivos com presença de EP (n=13), grupo de pacientes depressivos com ausência de EP (n=7) e grupo de controles (n=10). Os pacientes foram avaliados por meio de Entrevista Clínica de acordo com os critérios diagnósticos do DSM-IV, para a confirmação do diagnóstico. Para avaliação da gravidade dos sintomas depressivos foi aplicada a Escala de Depressão de Hamilton (HAM-D21), sendo incluídos apenas pacientes com HAM-D21 17. A presença de EP foi confirmada através da aplicação do Questionário Sobre Traumas na Infância (QUESI). Foram utilizados também a Escala de Avaliação de Depressão de Montgomery-Asberg (MADRS), o Inventário de Depressão de Beck (BDI), o Inventário de Ansiedade de Beck (BAI), a Escala de Ideação Suicida de Beck (BSI), a Escala de Desesperança de Beck (BHS), a Escala Hospitalar de Ansiedade e Depressão (HAD) e a Escala de Impulsividade de Barratt (BIS-11) para a avaliação de sintomas psiquiátricos. A avaliação endócrina foi controlada por placebo, cego por parte dos controles e pacientes, não randomizado, com desenho de medidas repetidas, onde os efeitos da Fludrocortisona (0.5 mg) e da Dexametasona (0.5 mg) foram avaliados através do cortisol salivar e plasmático. A secreção de cortisol plasmático e salivar foi avaliada nos sujeitos, após a administração de uma cápsula de Placebo, Fludrocortisona e Dexametasona às 22hs do dia anterior. O cortisol salivar foi coletado às 22h, ao acordar, 30 e 60 minutos após acordar e antes da coleta plasmática, nos dias seguintes após os desafios. Resultados: Na amostra de pacientes depressivos e controles, encontramos níveis significativamente menores de cortisol salivar ao acordar após a administração de Placebo nos pacientes depressivos comparados aos controles. Encontramos também uma tendência dos pacientes apresentarem níveis maiores de cortisol salivar ao acordar do que os controles após a administração de Dexametasona. Quando avaliado o cortisol após a administração de Fludrocortisona, os pacientes apresentaram níveis significativamente menores de cortisol salivar 30 minutos após acordar e na Área Sob a Curva (AUC) do que os controles. Além disso, encontramos também uma tendência dos pacientes depressivos apresentarem níveis menores de cortisol salivar 60 minutos após acordar do que os controles. Quando comparados entre pacientes depressivos com presença e ausência de EP e controles, encontramos uma tendência dos pacientes depressivos com ausência de EP apresentarem níveis menores de cortisol salivar ao acordar após Placebo do que os controles. As médias dos níveis de cortisol salivar ao acordar não diferiram entre os pacientes com presença de EP e os controles e entre os pacientes do grupo presença e ausência de EP. Com relação aos níveis de cortisol salivar após a administração de Dexametasona entre pacientes depressivos com presença e ausência de EP e controles, os pacientes depressivos com ausência de EP apresentaram níveis significativamente maiores de cortisol salivar ao acordar do que os controles. Encontramos também uma tendência dos pacientes com ausência de EP apresentarem níveis maiores de cortisol salivar ao acordar do que os pacientes com presença de EP, porém não foram encontradas diferenças significativas entre os pacientes com presença de EP e os controles. Conclusão: Nossos dados demonstram uma hipoatividade do eixo HPA nos pacientes depressivos. Além disso, estes achados sugerem que esta desregulação do eixo HPA se deva em parte a uma diminuição da sensibilidade dos RG e uma hiperativação dos RM nos pacientes depressivos. No entanto, quando comparados pacientes depressivos com presença e ausência de Estresse Precoce, os desafios com agonistas seletivos como a Dexametasona (agonista RG) e a Fludrocortisona (agonista RM) não foram capazes de detectar esta diferença fisiopatológica e distinguir entre os diferentes tipos de psicopatologia. Dessa forma, estes resultados sugerem que estudos com um agonista misto (RG/RM) como a Prednisolona teriam potencial para distinguir os pacientes depressivos com presença de Estresse Precoce. / Introduction: Several studies suggest that stress in early stages of development can induce persistent changes in the ability of the Hypothalamic-Pituitary-Adrenal (HPA) axis to respond to stress in adulthood. The imbalance of cortisol has been identified as a biological correlate of depressive disorders. These abnormalities seem to be related to changes in the ability of circulating glucocorticoids to practice their negative feedback on the secretion of HPA axis hormones through connecting to the mineralocorticoid receptor (MR) and glucocorticoid (GR) in the tissues of HPA axis. Due to the wide variety of stressors, as well as the different subtypes of depression, the findings of current studies have been inconsistent. Thus, more studies need to be able to elucidate the mechanisms involved in the association between Early Life Stress (ELS) and the development of depression. Objective: The objective this study is to evaluate the correlation between of Early Life Stress and changes in Hypothalamic-Pituitary-Adrenal axis and at receptors function glucocorticoid and mineralocorticoid in depressive patients. Methodology: We recruited 30 subjects initially divided into two groups: patients with current depressive episode (n =20) and control group (n = 10) Subsequently, patients were divided into two groups according to the ELS, making the final sample of three groups: depressive patients with ELS (n =13) group of depressive patients without ELS (n=7) and control group (n=10). Patients were evaluated by clinical interview according to the diagnostic criteria of DSM-IV to confirm the diagnosis. To evaluate the severity of depressive symptoms was applied to the Hamilton Depression Scale (HAM-D21), and included only patients with HAM-D21 17. The presence of ELS was confirmed by the Childhood Trauma Questionnaire (CTQ). We also used the Depression Rating Scale Montgomery-Asberg (MADRS), the Beck Depression Inventory (BDI), the Beck Anxiety Inventory (BAI), the Scale for Suicide Ideation Beck (BSI), the Scale Beck Hopelessness (BHS), the Hospital Anxiety and Depression Scale (HADS) and the Barratt Impulsiveness Scale (BIS-11) for the assessment of severity psychiatric symptoms. Endocrine evaluation was placebo-controlled, blinded by the patients and controls, non-randomized design with repeated measures, where the effects of Fludrocortisone (0.5 mg) and dexamethasone (0.5 mg) were assessed using salivary cortisol and plasma. The secretion of plasma cortisol and salivary was evaluated in the subjects, after administration of a capsule of Placebo, Fludrocortisone and Dexamethasone to 22hs the previous day. The salivary cortisol was collected at 22h, on waking, 30 and 60 minutes after waking and before plasma collection in the following days after the challenges. Results: In these sample of depressed patients and controls, we found significantly lower levels of salivary cortisol around waking after administration of Placebo in depressed patients than controls. We also found a trend for patients to have higher levels of salivary cortisol than controls on awakening after administration of Dexamethasone. When measured cortisol after administration of Fludrocortisone, patients showed significantly lower levels of salivary cortisol 30 minutes after waking and the Area Under the Curve (AUC) than controls. In addition, we also found a tendency for depressed patients showed lower levels of salivary cortisol 60 minutes after awakening than controls. When compared between depressed patients with and without ELS and controls, we found a tendency for depressed patients without ELS presented lower levels of salivary cortisol on awakening after Placebo than controls. The mean salivary cortisol levels on waking did not differ between patients with ELS and controls and between patients with and without ELS. The levels of salivary cortisol after Dexamethasone administration between depressed patients with and without ELS and controls, depressed patients without ELS had significantly higher levels of salivary cortisol on awakening than controls. We also found a trend for patients without Early Life Stress have higher levels of salivary cortisol upon waking than patients with Early Life Stress, but there were no significant differences between patients with Early Life Stress and controls. Conclusion: Our data show a hypoactivity of the HPA axis in depressed patients. Moreover, these findings suggest that this dysregulation HPA axis is partly due to a decrease the sensitivity of RG and a hyperactivation of MR in patients depressive. However, when compared depressed patients with and without Early Life Stress, the challenges with selective agonists as the Dexamethasone (agonist GR) and Fludrocortisone (agonist MR) were not able to detect this difference pathophysiological and distinguish between the different types of psychopathology. Thus, these results suggest that studies with a mixed agonist (GR/MR) such as Prednisolone have potential to distinguish of depressive patients with Early Life Stress.
139

A neurobiologia da depressão em pacientes com estresse precose: o papel do eixo HPA e da função dos receptores glicocorticóides (GR) e mineralocorticóides (MR) / Neurobiology of Depression in Patients with Early Life Stress: the Role of the HPA Axis and Glucocorticoid (GR) and Mineralocorticoid (MR) Receptor Function

Baes, Cristiane von Werne 24 June 2016 (has links)
Introdução: Crescentes evidências indicam que o abandono e o abuso infantis são fatores de risco para transtornos psiquiátricos. Estudos realizados tanto em animais como em humanos sugerem que o estresse nas fases iniciais de desenvolvimento pode induzir alterações persistentes na capacidade do eixo HPA em responder ao estresse na vida adulta e que esse mecanismo pode levar a uma maior suscetibilidade à depressão. Esta desregulação do eixo HPA parece estar relacionada às mudanças na capacidade dos glicocorticóides circulantes em exercer seu feedback negativo na secreção dos hormônios do eixo HPA por meio da ligação aos receptores de mineralocorticóides (MR) e glicocorticóides (GR) nos tecidos do eixo HPA. Objetivo: O objetivo deste trabalho foi avaliar a resposta do eixo HPA frente aos agonistas e antagonistas dos GR e MR em pacientes depressivos com e sem estresse precoce (EP) e controles. Metodologia: Selecionamos uma amostra total de 75 sujeitos composta por um grupo de pacientes com diagnóstico de episódio depressivo atual (n=47) e um grupo de controles saudáveis (n=28). Os pacientes foram divididos em 2 grupos de acordo com o estresse precoce: um grupo de pacientes depressivos com EP (n=33) e um grupo de pacientes depressivos sem estresse precoce (n=14). Os pacientes foram avaliados por meio da Mini Entrevista Neuropsiquiátrica Internacional (MINI-Plus), para a confirmação do diagnóstico. Para avaliação da gravidade dos sintomas depressivos foi aplicada a Escala de Depressão GRID de Hamilton (GRID-HAM-D21), sendo incluídos apenas pacientes com HAM-D21>=16. Para a avaliação do estresse precoce foi aplicado o Questionário Sobre Traumas na Infância (CTQ). Utilizamos também a Escala de Avaliação de Depressão de Montgomery-Asberg (MADRS), o Inventário de Depressão de Beck (BDI-II), o Inventário de Ansiedade de Beck (BAI), a Escala de Desesperança de Beck (BHS), a Escala de Ideação Suicida de Beck (BSI), a Escala de Impulsividade de Barratt (BIS-11) e o Questionário de Qualidade de Sono de Pittsburg (PSQI), para a avaliação dos sintomas psiquiátricos. A avaliação endócrina foi controlada por placebo, cego por parte dos controles e pacientes, não randomizada, onde os efeitos da fludrocortisona (0.5 mg), da prednisolona (5 mg), da dexametasona (0.5 mg) e da espironolactona (400mg) foram avaliados através do hormônio adrenocorticotrópico (ACTH) plasmático, do cortisol plasmático e salivar, da prolactina plasmática e do sulfato de desidroepiandrosterona (DHEA-S) plasmático. A secreção de cortisol salivar e dos hormônios plasmáticos foi avaliada em todos os sujeitos, após terem tomado no dia anterior às 22h: uma cápsula de placebo, fludrocortisona, prednisolona, dexametasona e espironolactona. A secreção de cortisol salivar foi avaliada às 22h após a tomada da medicação ou do placebo, ao acordar, 30 e 60 min após acordar e às 9h (antes da coleta plasmática), para avaliação da resposta do cortisol ao acordar (CAR) e do ritmo circadiano do cortisol (RC). Foi realizado também uma coleta plasmática as 9h nos dias seguintes após os desafios para medir o cortisol plasmático, o ACTH, o DHEA-S e a prolactina. Resultados: Os pacientes depressivos apresentaram níveis basais menores de cortisol salivar, de prolactina e de DHEA-S e níveis maiores na relação cortisol/DHEA-S. Não foram encontradas diferenças entre os pacientes depressivos e os controles nos níveis basais de ACTH, de cortisol plasmático, na CAR e no RC. Os pacientes depressivos apresentaram níveis menores de ACTH e de DHEA-S após a dexametasona e a fludrocortisona e tenderam a apresentar níveis menores de cortisol salivar após a fludrocortisona. Após a espironolactona encontramos níveis menores de ACTH, de cortisol salivar e de DHEA-S e níveis maiores no índice cortisol/DHEA-S nos pacientes depressivos. Os pacientes depressivos apresentaram também níveis menores de DHEA-S após a prednisolona, porém não foram encontradas diferenças entre os grupos nos demais hormônios avaliados após a prednisolona. Não foram encontradas diferenças no cortisol plasmático e na prolactina após os desafios entre os pacientes depressivos e os controles. Com relação à avaliação do estresse precoce nas medidas hormonais, encontramos uma tendência dos pacientes com EP apresentarem níveis menores basais de prolactina e após a fludrocortisona, a prednisolona, a dexametasona e a espironolactona do que os pacientes sem EP. No entanto, não foram encontradas diferenças entre os grupos nas demais medidas hormonais basais e após os desafios avaliadas neste estudo. Conclusão: Nossos achados fornecem evidências de que existem diversas alterações nas medidas hormonais relacionadas ao funcionamento do eixo HPA e de seus receptores GR e MR nos pacientes depressivos, associado à hipocortisolemia e um aumento do feedback inibitório mediado pelos GR e MR. Sugerem também o envolvimento da prolactina no desenvolvimento de quadros depressivos com estresse precoce, porém mais estudos são necessários para elucidarmos melhor a importância dos demais hormônios do eixo HPA e dos seus receptores em quadros depressivos com estresse precoce / Introduction: There are evidences indicating that child neglect and abuse are risk factors for psychiatric disorders. Studies that had as subjects animals or human suggest that stress in early phases of development may induce persistent changes in HPA axis response to stress in adulthood, which can lead to a greater susceptibility of developing depression. These abnormalities appear to be related to changes in the ability of circulating glucocorticoids and negative feedback on the secretion of HPA hormones through binding to glucocorticoid (GR) and mineralocorticoid receptors (MR) in HPA tissue. Aim: The aim of the present study was to assess HPA response after ingestion of GR and MR agonists and antagonists by depressive patients with and without early life stress (ELS) and controls. Methods: The sample was composed by a group of patients in current depressive episode (n=47), and a healthy control group (n=28). The depressed patients were divided in 2 groups, according to the presence or absence of ELS - a group with ELS (n=33) and a group without ELS (n=14). For diagnostic assessment, MINI International Neuropsychiatric Interview (MINI-Plus) was used. To assess the intensity of depressive symptoms, GRID-Hamilton Depression Rating Scale (GRIDHAM-D21) was applied, and for being included in the patient\'s group, subjects had to score >=16 in GRID-HAM-D21. To assess ELS, Childhood Trauma Questionnaire (CTQ) was applied. Other instruments were also used in the present study to assess psychiatric symptoms: Montgomery-Åsberg Depression Rating Scale (MADRS), Beck Depression Inventory II (BDI-II), Beck Anxiety Inventory, Beck Hopelessness Scale (BHS), Beck Scale for Suicide (BSI), Barratt Impulsiveness Scale (BIS-11), and Pittsburg Sleep Quality Index (PSQI). The neuroendocrine assessment was controlled using placebo, blind to subjects, and non-randomized. The effects of fludrocortisone (0.5 mg), prednisolone (5 mg), dexamethasone (0.5 mg), and spironolactone (400mg) were assessed by measuring plasmatic adrenocorticotropic hormone (ACTH), plasmatic and salivary cortisol, plasmatic prolactin, and plasmatic dehydroepiandrosterone sulfate (DHEA-S). The secretion of all plasmatic hormones was assessed in all subjects in blood collection sample at 9AM, after they took a pill containg placebo or fludrocortisone or prednisolone or dexamethasone or spironolactone, the day before, at 10 PM. The secretion of salivary cortisol assessed the day before 10 PM (after the ingestion of the pill), upon awakening, 30 minutes and 60 minutes after awakening, and at 9AM (before plasmatic collection), for assessed the cortisol awakening response (CAR) and the cortisol circadian rhythm (CR). At 9 AM there was a blood sample collection to assess plasmatic cortisol, ACTH, DHEA-S and prolactin. Results: Depressive patients presented lower basal levels of salivar cortisol, plasmatic prolactin and DHEA-S, and higher levels in the ratio cortisol/DHEA-S. There were no differences between depressive patients and healthy controls in basal levels of ACTH, plasmatic cortisol, in CAR, and in CR. Depressive patients had lower levels of ACTH and DHEA-S after dexamethasone and fludrocortisone, and there was a tendency of having lower salivary cortisol levels after fludrocortisone. After spironolactone, lower levels of ACTH, salivary cortisol, DHEA-S were found, and higher levels in ratio cortisol/DHEA-S were found in depressive patients. These patients also presented lower levels of DHEA-S after prednisolone, although there were no differences between groups concerning the levels of other hormones assessed after prednisolone. There were no differences found in plasmatic cortisol and prolactin levels after all challenges between depressive patients and controls. Considering ELS and hormonal level assessment, there was a tendency of patients with ELS of presenting lower levels of prolactin after placebo, fludrocortisone, prednisolone, dexamethasone, and spironolactone than patients without ELS. Nevertheless, there were no differences between these groups concerning the other hormonal basal levels and after the pharmachological challenges. Conclusion: Our findings provide evidence that there are several changes in hormonal levels related to the functioning of the HPA axis and its receptors GR and MR in depressive patients associated to hypocortisolism and the increase of negative feedback MR- and GR- mediated. Our data also suggest the role of prolactin in the development of depressive disorder with ELS, however, more studies are needed to better highlight the importance of other hormones of HPA axis and its receptors in depressive disorders with ELS
140

Participação do eixo hipotálamo-pituitária-adrenal na Doença Inflamatória Intestinal induzida experimentalmente / Participation of the hypothalamic-pituitary-adrenal axis in experimentally induced inflammatory bowel disease

Souza, Patrícia Reis de 06 August 2015 (has links)
As doenças inflamatórias intestinais (DII) são causadas por desequilíbrio entre as respostas imunes efetoras e reguladoras na mucosa intestinal e podem ser moduladas pelo eixo hipotálamo-hipófise-adrenal (HPA) por meio de interações neuroimunoendócrinas e secreção de cortisol. Embora os glicocorticóides (GC) sejam utilizados para tratar a DII, o cortisol produzido pelas glândulas supra-renais também está envolvido na resposta ao estresse, que pode levar a doenças inflamatórias descontroladas. Portanto, o objetivo deste trabalho é avaliar a participação do eixo HPA na modulação da resposta imune de mucosa intestinal. Para tal, camundongos C57BL/6 foram submetidos à remoção das glândulas adrenais seguida por indução de colite pela administração de água contendo 3% de dextran sulfato de sódio (DSS). Os resultados demonstraram que a ausência das adrenais levou à maior suscetibilidade à doença e mortalidade precoce, fenômeno que não foi prevenido pela reposição de GC. Os animais adrenalectomizados com colite apresentaram níveis significativamente menores de LPS, concomitantemente ao aumento de IL-6 no soro quando comparados aos camundongos não adrenalectomizados. Além disso, os animais adrenalectomizados apresentaram menor celularidade na lâmina própria (LP), menos áreas de erosão e menor escore histopatológico associado ao aumento de IFN-? e FasL, no intestino, sem produção local compensatória de corticosterona. Houve aumento na atividade das enzimas mieloperoxidase (MPO), N- acetilglicosaminidase (NAG) e eosinófilo-peroxidase (EPO) no intestino dos animais expostos ao DSS quando comparados ao grupo de camundongos controles saudáveis, independentemente da presença do eixo HPA intacto e o tratamento com GC nos animais adrenalectomizados levou à redução significativa da atividade de MPO. Também foi observado na LP dos camundongos adrenalectomizados aumento significativo na frequência de células dendríticas tolerogênicas CD11b+CD11c+CD103+, T auxiliares (CD3+CD4+), T citolíticas (CD3+CD8+) e NKT (CD3+CD49b+), além de redução significativa da população de células dendríticas pró-inflamatórias CD11b+CD11c+CD103-, leucócitos CD11b+ e linfócitos intra-epiteliais, de maneira dependente de GC. A ausência do eixo HPA intacto levou à diminuição de leucócitos totais no baço quando comparados ao grupo com colite, relacionada principalmente à redução significativa na frequência de células NKT (CD3+CD49b+), as quais foram restauradas nos camundongos tratados com GC exógenos. Durante a exposição ao DSS houve aumento de células Th2 e Th1 no baço dos camundongos não adrenalectomizados, enquanto que a remoção das adrenais levou a notável redução na população de células T CD4 produtoras de IL-4, IL-10, IFN-? ou IL-17, com aumento de células Th17 e diminuição significativa de células Th1 no baço dos camundongos adrenalectomizados e tratados com GC. De forma interessante, houve menor acúmulo de células T reguladoras juntamente à redução na intensidade média de fluorescência (MFI) de FOXP3 em células T CD4+CD25+ do baço dos camundongos adrenalectomizados expostos ao DSS, de maneira geral dependente de GC. Por fim, esta diminuição de mecanismos reguladores foi acompanhada de menor índice de proliferação e aumento de IL-10 no sobrenadante de cultura de esplenócitos de camundongos com o eixo HPA não ii funcional, indicando que a ausência de GC endógenos pode alterar significativamente a homeostase do sistema imunológico. Juntos, nossos resultados demonstram que o eixo HPA é importante na modulação da resposta imunológica durante a colite induzida experimentalmente / Inflammatory bowel diseases (IBD) are caused by imbalance between regulatory and effector immune responses in the intestinal mucosa and can be modulated by the hypothalamic-pituitary-adrenal (HPA) axis via neuroimmune endocrine interactions and secretion of cortisol. Although glucocorticoids (GC) are used to treat IBD, cortisol produced by the adrenals glands is also involved in the stress response, which can lead to uncontrolled inflammatory diseases. Therefore, the aim of this study was to evaluate the HPA axis in the modulation of the immune response of intestinal mucosa. C57BL/6 mice were subjected to removal of the adrenal glands followed by induction of colitis by administration of water containing 3% dextran sulfate sodium (DSS). The results showed that the absence of adrenals led to increased susceptibility to disease and early mortality, a phenomenon that was not prevented by GC replacement. Adrenalectomized animals exposed to DSS had significantly lower levels of LPS, concomitantly to increased IL-6 in the serum when compared to non-adrenalectomized mice. In addition, adrenalectomized animals had lower cellularity in the lamina propria (LP), less erosion areas and less histopathologic score associated with increased IFN-? and FasL in the intestine, without compensatory local production of corticosterone. There was an increase in the activity of the myeloperoxidase (MPO) enzyme, N- acetilglicosaminidase (NAG) and eosinophil-peroxidase (EPO) in the intestines of DSS-exposed animals when compared to the healthy control group of mice, regardless of the presence of intact HPA axis, while treatment with GC led to significantly reduced MPO activity. It was also observed in the LP of adrenalectomized mice significant increase in the frequency of tolerogenic dendritic cells CD11b+CD11c+CD103+, helper T (CD3+ CD4+), cytolytic T (CD3+ CD8+) and NKT (CD3+ CD49b+) besides significant reduction in the population of pro-inflammatory dendritic cells CD11c+ CD11b+ CD103-, leukocyte CD11b+ and intraepithelial lymphocytes, GC-dependent manner. The absence HPA intact carried decrease in total leukocytes in spleen when compared to the group with colitis, related mainly to significant reduction in the frequency of NKT cells (CD3+CD49b+), which were restored in the GC treated mice. During exposure to DSS there was increased Th2 and Th1 cells in the spleen of non-adrenalectomized mice, while the removal of the adrenals was associated to a marked reduction in the population of CD4 T cells producing IL-4, IL-10, IFN-? or IL-17 with increased Th17 cells and significant decrease in Th1 cells in the spleen of adrenalectomized mice treated with GC. Interestingly there was less accumulation of regulatory T cells together to a reduction in mean fluorescence intensity (MFI) of FOXP3 in CD4+CD25+ T cells in the spleen of mice exposed to DSS after adrenalectomy, most dependent on GC. Finally, the decline of regulatory mechanisms was accompanied by lower rates of proliferation and increased IL-10 in the supernatant culture of splenocytes of mice with disrupted HPA axis, indicating that the absence of endogenous GC altered significantly the homeostasis of the immune system. Together, our results demonstrate that the HPA axis is important in modulating the immune response during experimentally induced colitis

Page generated in 0.0478 seconds