O eixo hipotálamo-pituitária-adrenal é o principal sistema neuroendócrino envolvido na regulação e adaptação da resposta ao estresse e, o principal hormônio secretado é o cortisol. O cortisol exerce seus efeitos por meio dos receptores mineralocorticoide (MR) e glicocorticoide (GR). Variações nos genes desses receptores têm sido associadas à sensibilidade aos glicocorticoides e mudanças no perfil metabólico. O objetivo geral desse trabalho foi compreender a variabilidade existente em relação às respostas fisiológicas de bovinos por meio da identificação de polimorfismos genéticos em genes envolvidos na resposta ao estresse e, verificar as consequências dessa variação genética em características de qualidade da carne. Dessa forma, três abordagens foram propostas: (1) avaliar a incidência de carne DFD (dark, firm and dry) e seu impacto no perfil metabólico, endócrino e características de qualidade da carne bovina, uma vez que o estresse é um dos principais fatores que levam a essa condição desfavorável; (2) avaliar a contribuição de fatores genéticos, por meio da identificação de polimorfismos de nucleotídeo único (SNPs), no gene do MR e GR, e suas associações com as características mensuradas; (3) avaliar os efeitos desses polimorfismos sobre o perfil proteico do músculo bovino. Foram utilizados 241 bovinos da raça Nelore. Os resultados evidenciaram implicações direta do pH 24 horas post-mortem nos atributos de cor e perdas por cozimento da carne. A incidência de carnes DFD (pH>=5,8) foi de 18,7%. Os polimorfismos identificados mostraram influenciar em algumas características mensuradas. Os SNPs NR3C2_1 e NR3C2_2 no gene do MR foram associados ao conteúdo de glicogênio muscular e nível plasmático do hormônio adrenocorticotrófico (ACTH) post-mortem, e o SNP NR3C1_1 no gene do GR foi associado aos níveis plasmático de cortisol post-mortem. As análises proteômicas demonstraram que a maioria das proteínas reguladas por esses SNPs estão envolvidas na contração muscular, metabolismo e defesa celular. Portanto, é possível inferir que o pH tem impacto nas características de qualidade da carne e que polimorfismos em MR e o GR levam a mudanças na atividade do eixo HPA, no perfil metabólico do organismo e no perfil proteico do músculo, sugerindo que esses genes estão envolvidos em uma complexidade de funções e podendo ser alvos de estudos em sistemas de produção que visam melhorar a produtividade. / The hypothalamic-pituitary-adrenal axis is the main neuroendocrine system involved in the regulation and adaptation in stress response and the primary hormone secreted is cortisol. Cortisol exerts its effects through the mineralocorticoid (MR) and glucocorticoid (GR) receptors. Variations in the genes of these receptors have been associated with sensitivity to glucocorticoids and changes in the metabolic profile. The general objective of this work was to understand the variability in relation to physiological responses of cattle through identification of genetic polymorphisms in genes involved in stress response and, checking the consequences of this genetic variation in meat quality traits. Thus, three approaches have been proposed: (1) evaluate the incidence of DFD meat (dark, firm and dry) and its impact on metabolics, endocrines profiles and meat quality traits, since stress is the major factor that lead to this unfavorable condition; (2) evaluate the contribution of genetic factors through identification single nucleotide polymorphisms (SNPs) in the MR and GR gene and its association with the measured traits; (3) evaluate the effects of these polymorphisms on the protein profile of bovine muscle. A total of 241 Nellore cattle were used. The results evidenced direct implications of 24 hours pH post-mortem in color attributes and cooking losses. The incidence of DFD meat (pH >= 5.8) was 18.7%. The polymorphisms identified demonstrated to influence some on measured characteristics. The NR3C2_1 and NR3C2_2 SNPs in MR gene were associated with muscle glycogen content and post-mortem adrenocorticotropic hormone (ACTH) plasma levels and, the NR3C1_1 SNP in GR was associated with post-mortem cortisol plasma levels. The proteomic analysis demonstrated that most proteins regulated by these SNPs are involved in muscle contraction, metabolism and cellular defense. Therefore, it is possible to infer that pH has impact on meat quality traits and MR and GR polymorphisms lead to changes in the HPA axis activity, metabolic profile and protein muscle profile, suggesting that these genes are involved in a complexity of functions and may be targets for studies on production systems to improve productivity.

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.

Ecstasy é o nome popular do 3,4-metilenodioximetanfetamina (MDMA), uma droga de abuso utilizada por adultos jovens. Diversos relatos têm mostrado existência de correlações positivas entre o abuso do Ecstasy e o aparecimento de doenças infecciosas. Muitos estudos em modelos animais mostram que o MDMA induz alterações de imunidade inata e adquirida; entretanto pouco se sabe sobre os mecanismos pelos quais estes efeitos ocorrem. Desta forma, buscamos neste trabalho os mecanismos neuroimunes pelos quais o MDMA diminui a atividade de neutrófilos e altera a distribuição de leucócitos nos diferentes compartimentos imunes. Além disso, avaliamos se os efeitos induzidos pelo MDMA afetam a resposta a uma infecção experimental induzida por Listeria monocytogenes. Nossos resultados mostram que 60 minutos após a administração de MDMA na dose 10mg/kg, houve 1) diminuição do burst oxidativo de neutrófilos induzido por SAPI e PMA e, também, da porcentagem e da intensidade da fagocitose dos neutrófilos sanguíneos; 2) diminuição da celularidade total da medula óssea e aumento da mesma no baço, além de diminuição do peso relativo do baço; 3) aumento na porcentagem de neutrófilos e diminuição na porcentagem de linfócitos sanguíneos; e 4) diminuição da expressão de NFB de neutrófilos sanguíneos. O tratamento com metirapona ou RU-486 prévio ao tratamento com MDMA foi capaz de inibir 5) os efeitos observados em todos os parâmetros avaliados na diminuição da atividade de neutrófilos; 6) as alterações das porcentagens de neutrófilos e linfócitos sanguíneos e 7) a diminuição da expressão de NFB. Observamos, ainda, que o tratamento com 6-OHDA ou ICI-118,551 prévio ao tratamento com MDMA 8) não foram capazes de inibir os efeitos induzidos pelo MDMA na atividade de neutrófilos e na contagem diferencial de leucócitos sanguíneos; no entanto, 9) preveniram as alterações de celularidade induzidas por MDMA na medula óssea e no baço, e 10) a diminuição do peso relativo do baço. Por fim, observamos em um modelo de infecção experimental por LM que o MDMA 11) induziu mielosupressão (diminuição do CFU na medula óssea e aumento no baço); 12) diminuiu o número de leucócitos sanguíneos e a celularidade da medula óssea; 13) aumentou a celularidade do baço; 14) diminuiu a produção de citocinas pró-inflamatórias (IL-12p70, TNF, IFN-, IL-6) e quimiocina (MCP-1) nas primeiras 24 h; e 15) aumentou a produção das mesmas citocinas e quimiocina após 72 h da indução da infecção. Desta forma, concluímos que os efeitos induzidos pelo MDMA sobre a atividade de neutrófilos foram provavelmente mediados pela diminuição da expressão de NFB induzido pela ação da corticosterona e que a corticosterona, também está envolvida com as alterações na contagem diferencial de neutrófilos e linfócitos. As catecolaminas periféricas responderam pelas alterações na distribuição de leucócitos entre baço e medula óssea, e diminuição do peso relativo do baço. Além disso, o MDMA pode ser considerado uma droga imunossupressora visto que diminuiu a resistência a uma infecção por LM por mecanismos neuroimunes / Ecstasy is the popular name of 3,4-metylendioxymetamphetamine (MDMA), a drug of abuse mainly used by young adults. Several reports have shown the existence of a positive correlation between Ecstasy abuse and increased susceptibility to infectious diseases. Some studies using animal models report that MDMA induces alterations in both innate and adaptive immunity, however little is known about the mechanisms that generate such alterations. Therefore, we sought for neuroimmune mechanisms that could be involved in the previously reported decreasing on neutrophil activity and alteration in the leukocyte distribution. Moreover, we analyzed the host resistance to Listeria monocytogenes after MDMA treatment. We show that MDMA (10 mg/kg), 60 min after administration: 1) decreases SAPI and PMA-induced oxidative burst and percentage/intensity of phagocytosis of circulating neutrophils; 2) decreases bone marrow cellularity while increases it in the spleen, and also decreases spleen relative weight; 3) increases neutrophil percentage while decreases lymphocyte percentage in the blood; and 4) decreases NFB expression on circulating neutrophils. Metyrapone or RU-486 prior to MDMA treatment abrogates 5) the MDMA effects previously reported on neutrophil activity; 6) alterations in the percentage of circulating neutrophils and lymphocytes, and 7) decreasing of NFB expression. We also show that 6-OHDA or ICI-118,551 prior to MDMA treatment were not able to 8) abrogated the MDMA effects previously reported on neutrophil activity and blood leukocyte differential counts; nevertheless, 9) they abrogated the previously reported alterations on bone marrow and spleen cellularity, and 10) reduction on spleen relative weight. Finally, in a model of host resistance to Listeria monocytogenes we show that MDMA: 11) induces myelosuppression by decreasing CFU on bone marrow while increasing it on spleen; 12) decreases circulating leukocytes and bone marrow cellularity; 13) increases spleen cellularity; 14) decreases pro-inflammatory cytokines production (IL-12p70, TNF, IFN-, IL-6) and chemokine (MCP-1) after 24h of the infection; and 15) increases the production of the pro-inflammatory cytokines and chemokines previously reported after 72h of the infection. Thus, we conclude that the MDMA effects on neutrophil activity were mediated by the reduction of NFB expression, and this effect was induced by corticosterone elevation in the serum. Corticosterone is also involved in the alterations on neutrophil and lymphocyte counts. Catecholamines were shown to be involved in the alterations on leukocyte distribution in the bone marrow and spleen, and in the reduction of relative weight of spleen. Additionally, MDMA reduced the host resistance to Listeria monocytogenes. Therefore, MDMA can be considered an immunosuppressive drug and those effects are mediated by neuroimmune mechanisms

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

Background/Aims: Little research effort has so far been dedicated to the analysis of the hypothalamic-pituitary-adrenal axis of aetiologically differing subgroups of patients with panic disorder (PD). The current study aimed at a deeper understanding of the cortisol stress response in cannabis-induced PD (CIPD) patients. Methods: Matched groups of 7 PD patients (mean age ± SD: 32.95 ± 9.04 years), 7 CIPD patients (31.94 ± 8.40 years), and 7 healthy controls (HC) (31.13 ± 8.57 years) were included in the study. The Trier Social Stress Test (TSST) was used for stress induction. Salivary cortisol samples were collected and panic- and depression-related questionnaires were applied. Results: A stress response to the TSST was found in 28.6% of PD patients, in 51.1% of CIPD patients, and in 100% of HC subjects. Statistical analyses revealed a cortisol hyporesponsiveness in PD and CIPD patients. While cortisol values of PD patients and HC participantsdiffered significantly, CIPD patients’ cortisol courses balanced between those of PD patients and HC subjects. Conclusions: Current findings show a distinctive pattern of the stress-induced cortisol reaction in CIPD patients, which is markedly different from the hormonal response in PD patients as well as HC subjects. Previous findings of cortisol hyporesponsiveness in PD patients compared to HC subjects were confirmed.

[pt] Os transtornos de ansiedade afetam milhares de pessoas em todo o mundo, sendo representados como um dos principais distúrbios mentais. A ansiedade é acompanhada por uma série de respostas comportamentais e fisiológicas, quando na presença de estímulos aversivos. Essas respostas provocam ações neuroendócrinas envolvendo o sistema nervoso simpático (SNS), o eixo hipotálamo-pituitária-adrenal (HPA) e o sistema renina-angiotensina (SRA). Pesquisas feitas em modelos animais possibilitam uma melhor compreensão dos mecanismos neurofisiológicos e comportamentais associados à patologias observadas em humanos. Os animais Cariocas com Alto Congelamento (CAC) e Cariocas com Baixo Congelamento (CBC) são duas linhagens condicionadas de ratos que apresentam, respectivamente, níveis altos ou baixos de respostas semelhantes à ansiedade. O presente estudo investigou os efeitos da Losartana e Valsartana, sendo ambas da classe antagonistas do receptor de angiotensina II, na modulação da ansiedade nos ratos CAC, CBC e ratos controle. O tratamento crônico com Losartana e o tratamento agudo com Valsartana não produziram efeitos significativos nas respostas comportamentais associadas à ansiedade no condicionamento de medo contextual, campo aberto e labirinto em cruz elevado. Nossos dados sugerem que nas doses e duração dos tratamentos, a administração destes medicamentos anti-hipertensivos não é capaz de modular a ansiedade nos animais CAC e CBC. / [en] Anxiety disorders affect thousands of people all around the world, being represented as the most common of mental disorders. Anxiety is associated with a number of behavioral and physiological responses when faced with aversive stimuli. These responses provoke neuroendocrine actions involving the activation of the sympathetic nervous system (SNS), the hypothalamic-pituitary-adrenal axis (HPA) and the renin-angiotensin system (RAS). Studies on animal models allow for a better understanding of the neurophysiological and behavioral mechanisms associated with pathologies observed in humans. The Carioca High Freezing (CHF) and Carioca Low Freezing (CLF) are two conditioned strains of rats that present, respectively, high or low levels of anxiety-like responses. The present study investigated the effects of Losartan and Valsartan, both angiotensin II receptor blockers, on the modulation of anxiety-like behaviors of CHF, CLF and control rats. Neither chronic treatment of Losartan nor acute treatment of Valsartan yielded significant effects on anxiety measurements in the contextual fear conditioning, open field and elevated plus maze tests. Thus, our findings suggest that at the doses and durations of treatment tested, administration of these antihypertensive drugs did not play a modulating role of anxiety-like behaviors in CHF and CLF animals.

No description available.

<p>  </p> <p>Glucocorticoids (GC) play a critical role in regulating the physiological response to stress. Disruptions to baseline levels due to stress can have negative implications on a variety of factors including growth and development, physical body conditions, metabolism, immune functions, and expression of normal behaviors, although this list is not exhaustive. When birds are unable to adapt to the stressor and return to homeostasis, the energy expenditure associated with the failed attempt at coping can lead to significant declines in the overall health, welfare, production, and performance of the bird. This can go on to impact producers and consumers as well, indicating the extensive repercussions of stress. Recently, scientists have been investigating thorough and efficient methods of quantifying stress in birds, such as measuring heterophil-to-lymphocyte ratio (HLR) or detecting glucocorticoid levels through enzyme-linked immunoassays (ELISA). However, the precise mechanism behind HLR increase during stress is unknown and ELISAs may not provide accurate results depending on when the blood is being measured. </p> <p><br></p> <p>GC are differentially released and exert their effects in a manner that is dependent on sex, age, and time. However, before investigating this, it was critical to validate the GC kits to ensure that they were measuring cortisol and corticosterone separately along with zero cross reactions with other precursors. Chapter 2 had 4 experiments carried out. The objective of experiment 1 was to validate ELISAs to ensure that they were measuring the GC accurately and separately since both cortisol and corticosterone were being measured. To do this, duck serum was pooled and charcoal-stripped to remove the presence of steroids. 3 standard curves were run to confirm that there was no cross reactivity. The objective of experiment 2 was to further validate the ELISA kits with mass spectrometry by checking for both glucocorticoids in the pooled samples. Once the validation process was complete, experiment 3 was carried out to look at the effect of ACTH stimulation on GC release. 16-week-old drakes and hens were given either intramuscular (IM) injections of cosyntropin (0.06 mg/kg) or saline as control. The cosyntropin dose was chosen according to previous studies reporting relatively high physiological responses, therefore, we wanted to replicate this. N was 10/sex/treatment. Blood was then collected at 0, 1, and 2 hours after injections and serum was analyzed by ELISAs. Lastly for experiment 4, 14-week-old developer drakes and hens at Maple Leaf Farms were assessed for a transportation stress experiment. Blood from 10 ducks/sex/time/barn were collected at 24 hours before transport to the breeder barn, immediately after a 1-hour transport, 24 hours after, and 1 week after transport. The results from experiment 1 yielded that both cortisol and corticosterone can be measured without the presence of unwanted contaminants or other products. Experiment 2 identified the greater sensitivity of mass spectrometry when reading GC levels, although the differences were linear. Experiment 3 showed that serum corticosterone levels were significantly increased at 1 hour after ACTH injections in both drakes and hens, with levels continuing to increase for the drakes. Serum cortisol levels were significantly increased at 1 hour after ACTH injections in both sexes, however, the hens had greater levels compared to the drakes. Serum cortisol levels returned to levels similar to that of saline-injected ducks at the 2-hour mark. Lastly, the transportation stress portion showed that cortisol was released at about 1/3 of corticosterone levels in both sexes. Hens showed increased levels of serum corticosterone compared to drakes at all time points except for 1 week after transport, and also had significantly increased serum cortisol levels at all time points. In conclusion, the ELISA kits were verified for future use when measuring GC as well as mass spectrometry. GC were detected in the ACTH and transportation stress experiments with hens displaying a greater sensitivity to GC release due to increased circulating levels compared to drakes. Although it was nonsignificant, there was a trend for GC to increase in response to transport. </p> <p><br></p> <p>There are sex differences in GC release and HLR for Pekin ducks and various challenges from the studies support this. With hens showing increased sensitivity to stress and drakes with more transient and gradual levels, we have consistently seen that both GC have differential roles in the stress response and not only is it critical to study both hormones, the timing of when measurements are taken are important as well to get a clear understanding of when the stress response is initiated. </p> <p><br></p> <p>Chapter 3 went further to understand the response of GC and HLR. The objective was to  investigate the release of cortisol and corticosterone in response to an ACTH dose response challenge. In Chapter 2, only one dose of cosyntropin was used and sample collection times only went to 2 hours after injections. In this study, 2 additional doses and an extra hour of sample collection were added to obtain more information. Pekin ducks were either given IM cosyntropin injections or saline for control, with an N of 10/sex/treatment. There were 3 treatment doses: High (0.06 mg/kg), medium (0.03 mg/kg), and low (0.015 mg/kg). All injections were given promptly at 0730 hours. Blood was collected at 0, 1, 2 and 3 hours after injections from the tibia veins to obtain serum for ELISAs. Blood smears were done to analyze HLR and sent to an independent lab to obtain values. The results indicated that both GC had significant sex x dose x time interactions. The low dose injection had no effect on corticosterone in hens with a slight increase for drakes at the first hour. The high dose for hens led to a spike in corticosterone levels at the first hour with a gradual decrease, and drakes had an increase that lasted for 2 hours until they returned to baseline at the last hour. The high dose in drakes stimulated cortisol release during the first 2 hours after injection with a similar effect in hens. However, hens had elevated levels compared to drakes. Finally, there was no dose response effect for HLR, although interestingly, the low dose injection elevated HLR even though there was no effect in GC. There were sex differences in the HLR response where the drakes given the high dose had levels that plateaued by the third hour, while the hens still had elevated levels. In conclusion, the ACTH dose-response test identified that ACTH has a dose-dependent effect in both GC and sex differences in their release. HLR also showed sex differences that did not depend on the dose given.</p> <p><br></p> <p>Chapter 4 observed acute exposure of GC in ducks. Pekin ducks were assigned 10/sex/treatment to receive either IM control, cortisol, or corticosterone injections. In addition, a low-dose cortisol treatment was given to represent the endogenous levels of cortisol compared to corticosterone. The control injections contained safflower oil, which was chosen as vehicle due to the low levels of genistein present. This is important as genistein is a plant estrogen and this could interact with the GC and alter the results. Blood was collected at 0, 1, 2, and 3 hours after injections for serum analysis with ELISAs, and blood smears were collected for complete blood count (CBC) differentials. Significant sex x treatment x time interactions were notable in both GC. Hens had significant increases at the first hour after injections in all treatments compared to controls, and drakes had increases at 2 hours after injections in all treatments except the low-dose cortisol. </p> <p><br></p> <p>After observing the effect of acute stress in ducks, the next step was to investigate the effects of chronic stress in chapter 5. Adult breeder Pekin ducks were randomly distributed into 3 groups: corticosterone, cortisol, or control treatments. The GC were in crystalline steroid form distributed through 2 capsules that were subcutaneously implanted on the backs of the neck. The ducks in the control group were given empty capsules. Blood smears, blood draws for serum, egg collection, body weights, and organ samples were collected over a period of 2 weeks. For the results, the corticosterone implants elevated corticosterone levels in both sexes. Interestingly, cortisol levels were elevated in both GC treatments in both sexes. Cortisol elevated HLR in drakes 1 day after implants with no effect from corticosterone. Hens had elevated HLR from both GC at all timepoints throughout the experiment. There were no significant differences in morphometrics in either sex. Corticosterone was not present in eggs, but cortisol was elevated in the albumen on day 7 and 14 of the experiment. Overall, there were sex differences in HLR where hens had greater levels in both GC treatments.</p>

Hippocampal mineralocorticoid receptor mRNA expression was increased in male hamsters exposed to 18 days of short photoperiod relative to animals maintained under long day illumination (p < 0.05). Short day hamsters were also characterized by increased weight gain, and heavier adrenal glands (p < 0.05). The larger adrenals showed selective increases in the widths of the zonae reticularis and glomerulosa (p < 0.001). Incidences of torpor and reduced body temperature were observed in the short day animals. No changes were found in reproductive organ weights, systolic blood pressure, open-field behavior, or stress levels of plasma corticosteroids. We conclude that the hamster brain-adrenal axis responds rapidly to changes in photoperiod, raising the possibility that this axis is a primary mediator of shortened photoperiod responses.

No description available.