Dissertationen zum Thema „Estrogenic stress“

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A diminuição das concentrações plasmáticas de estrógeno está intimamente relacionada com o aumento do estresse oxidativo e a diminuição da massa muscular em idosos. A terapêutica hormonal estrogênica (THE) e o treinamento de força (TF) apresentam resultados efetivos sobre a manutenção do tecido muscular em idosos. No entanto, os mecanismos responsáveis pelas melhorias induzias por ambas as intervenções são pouco elucidados. Nesse sentido, avaliamos os efeitos da THE, do TF e a associação sobre a manutenção do tecido muscular esquelético de ratas periestropausadas. Ratas Wistar (18 meses) foram distribuídas em: Grupo não treinado (NT-Veh), Grupo NT tratado com a THE (NT-E2), Grupo TF (TF-Veh) e Grupo TF-E2. Os animais receberam a THE (17β estradiol; 2 x semana; 25 µg/kg/administração) e/ou praticaram TF (3 x semana; 80% sobrecarga) durante 16 semanas. A THE e o TF induzem benefícios ao tecido muscular esquelético de ratas periestropausadas, no entanto, por diferentes maneiras. Enquanto a THE induziu diminuição do estresse oxidativo muscular (Dihidroetidina), o TF resultou em melhoras significativas na função muscular, no sistema antioxidante muscular (Catalase) e na expressão de miRNAs (206, 146b e 133a). Já a interação das intervenções resultou em melhora no estado redox (Sirt1, Sirt3, PGC-1α, COXIV), na responsividade dos receptores estrogênicos (ERα, ERβ e GPR30), e atividade de vias de sinalização do tecido muscular (IGF-1/Akt-1/mTOR). Além disso, as intervenções de maneira isolada ou em associação, levaram ao aumento no percentual de fibras glicolíticas e redução das oxidativas. Sugerimos que a aderências das intervenções (associadas ou não) possam minimizar/atenuar a perda da massa muscular observada em fases tardias durante o processo de envelhecimento.
The decrease of estrogen (E2) circulating levels is strongly related to increased oxidative stress and the loss of muscle mass in elderly. The hormone replacement therapy (HRT) and strength training (ST) are the main effective interventions to prevent the loss of muscle mass, however, the mechanisms involved in interventions-induced benefits are not well elucidated. In this sense we evaluate the effect of HRT, ST and association on skeletal muscle maintenance of periestropaused rats. Female Wistar rats (18 months old) were randomly assigned into: non-exercised and non-treated group (NE-Veh), NE treated group (NE-E2), exercised and non-treated group (ST-Veh) and ST-E2 group. The animals received the HRT (17β estradiol; 2 x week; 50 µg/kg/week) and/or performed ST (3 x week, 80% overload) for 16 weeks. The HRT and ST promoted beneficial effects on skeletal muscle of periestropaused rats, however, by different manners. While HRT treatment leaves the reduction of oxidative stress (Dihidroetidine), the ST resulted in significate improvement on skeletal muscle function, in skeletal muscle antioxidant system (Catalase) and in miRNAs expression (2016, 146b and 133a). Already, the association of interventions resulted in improvement of redox state (Sirt1, Sirt3, PGC-1α, COXIV), in estrogen receptor responsiveness (ERα, ERβ and GPR30) and the activity of skeletal muscle signaling pathways (IGF-1/Akt-1/mTOR). In addition, the interventions, isolated or combinated, leaves an increase of the percentage of glycolytic fibers and reduced percentage of oxidative fibers. We suggest that the adherence to interventions (combinated or not) could minimize/attenuate the loss of skeletal muscle mass observed in later phases of aging process.
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Les travaux présentés dans cette thèse proposent d’évaluer l'impact d’un stress oestrogénique, durant des phases clés du cycle de vie des poissons (développement précoce et gamétogénèse), dans un contexte de changement global, tel que simulé par le scénario RCP8.5 du GIEC à l'horizon 2100 (+3 °C et -0.4 unité pH). Elle s’appuie sur une expérimentation en milieu contrôlé menée sur l’épinoche à trois épines (Gasterosteus aculeatus), permettant d’une part, l'exposition à des scénarios climatiques différents (actuel et RCP8.5) sur tout le cycle de vie de cette espèce et d’autre part, de combiner ce stress climatique à un stress oestrogénique (17α-ethynylestradiol = EE2 ; 15 ng.l-1) pendant les stades embryo-larvaires et en fin de gamétogénèse. L’impact du stress climatique, ou du multi-stress, a été abordé par une approche intégrative, s'appuyant sur des analyses physiologiques, biochimiques et moléculaires, permettant d’observer les effets sur la croissance, la reproduction et la survie à différents niveaux biologiques. En résumé, cette étude montre que des conditions de températures plus élevées et de pH plus bas augmentent les coûts métaboliques, affectant la croissance des juvéniles. Cet effet sur la croissance est accentué lors d’une contamination précoce à l’EE2. Au stade adulte, les coûts métaboliques générés par le stress climatique, impactent la maturité sexuelle et le succès reproducteur (diminution du nombre de femelles capables de se reproduire, retard et réduction de la période de ponte, maturation ovocytaire et qualité des oeufs amoindries). Ces effets ne sont pas modulés par le stress oestrogénique supplémentaire, appliqué en fin de gamétogénèse. Toutefois, la contamination pendant les stades précoces a entraîné des effets durables, comme une féminisation des mâles et une perturbation de l'axe de la reproduction, sans modulation par la condition climatique. Enfin, les deux principaux résultats sur la survie concernent, deux périodes : 1- En condition de stress climatique, un pic de mortalité a été observé après la reproduction, associé à la prolifération de Vibrio rotiferianus et à un état physiologique plus vulnérable des épinoches en période de post-reproduction et de températures plus élevées. 2- En condition de multistress où une mortalité totale des larves issues de parents contaminés à l’EE2 a été constatée suggérant un rôle crucial de l’exposition des géniteurs sur les réponses de la descendance. Ces travaux soulignent l’intérêt de considérer le multi-stress sur l’entièreté du cycle de vie pour estimer la vulnérabilité des espèces aquatiques dans un environnement futur
The work presented in this thesis aims to evaluate the effects of estrogenic stress during key phases of the fish life cycle (early development and gametogenesis) in the context of global change as simulated by the IPCC RCP8.5 scenario for the year 2100 (+3 °C and -0.4 pH units). It is based on a controlled environment experiment carried out on the three-spined stickleback (Gasterosteus aculeatus), which allows exposure to different climate scenarios (current and RCP8.5) throughout the life cycle of this species and, in addition, to combine this climatic stress with estrogenic stress (17α-ethynylestradiol = EE2 ; 15 ng.l-1) during the embryonic-larval stages and at the end of gametogenesis. The effects of climatic stress, or multistress, were addressed by an integrative approach based on physiological, biochemical and molecular analyses, allowing the observation of effects on growth, reproduction and survival at different biological levels. In conclusion, this study shows that higher temperature and lower pH conditions increase metabolic costs and thus affect juvenile growth. This effect on growth is exacerbated by early contamination with EE2. At the adult stage, the metabolic costs generated by climatic stress affect sexual maturity and reproductive success (reduction in the number of reproductive females, delay and reduction in the spawning period, impaired oocyte maturation and egg quality). These effects are not modulated by additional estrogenic stress applied at the end of gametogenesis. On the other hand, contamination during early stages resulted in permanent effects such as feminisation of males and disruption of the reproductive axis, without modulation by climatic conditions. Finally, the two main results on survival concern two periods: 1- Under climatic stress conditions, a post-reproductive mortality peak wasobserved, associated with the proliferation of Vibrio rotiferianus and a more vulnerable physiological state of the sticklebacks during the post-reproductive period and at higher temperatures. 2- Under multistress conditions, a total mortality of larvae from EE2-contaminated parents was observed, suggesting a critical role of parental exposure on offspring responses. This work highlights the importance of considering multi-stress throughout the life cycle to assess the vulnerability of aquatic species in a future environment

The present study was conducted to determine the effect of differential endogenous estrogen exposure in rats on stress-induced changes in spatial working memory. Subjects comprised male (n=8) and female (n=10) Sprague-Dawley rats, which were trained to complete a T maze, delayed alternation task. Performance was scored as a percentage of trials during which the correct maze arm was selected. Subjects scores were recorded after 1 and 2 hours of restraint stress, as well as after 1 hour of unimpeded movement in a cage placed in the testing room. Restraint stress was effected through physical confinement within plastic, cylindrical tubing. Female subjects underwent each of the testing conditions twice, during periods of high and low endogenous estrogen exposure, as ascertained by microscopic examination of vaginal epithelial cells for estrous cycle stage determination. Females in proestrus (elevated endogenous estrogen exposure) subjected to 1 hour of restraint performed significantly worse than their baseline scores (p=0.0017) or females in estrus (low endogenous estrogen exposure) after 1 hour of restraint (p=0.00014). After 1 hour of restraint, females in proestrus also committed an increased rate of perseverative errors compared to females in estrus, although this increase did not achieve statistical significance (p=0.06). No appreciable differences existed among subject groups in baseline performance or subsequent to 2 hours of restraint stress. Resultant data indicate impaired working memory among female rats under conditions of stress in the context of elevated endogenous estrogen exposure. This study, then, suggests a potential synergistic effect of stress and estrogen in compromising prefrontal cortex function and, therefore, may lend insight into the observed sex-related disparity in the incidence of major depressive disorder and other anxiety-related mood disorders.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior
O desempenho fisiolÃgico da atividade celular requer um equilÃbrio entre a produÃÃo de espÃcies de radicais livres e a sua desativaÃÃo por agentes reguladores e protetores. Quando esse equilÃbrio à quebrado, surge o estresse oxidativo. Diversos estudos experimentais utilizando estrÃgenos para a induÃÃo de distÃrbios ovarianos e metabÃlicos, com destaque para a SÃndrome dos OvÃrios PolicÃsticos (SOP), estÃo disponÃveis na literatura cientÃfica. A Metformina (MTF) à um anti-hiperglicemiante, frequentemente utilizado para tratamento da SOP, permitindo a restauraÃÃo da ciclicidade menstrual, induÃÃo da ovulaÃÃo e o aumento da ocorrÃncia de gestaÃÃo. Na Medicina Tradicional Chinesa, a Acupuntura (Ac) e a Eletroacupuntura (EAc) sÃo utilizadas na promoÃÃo do equilÃbrio orgÃnico, mediante estÃmulo de vias nervosas produtoras de neurotransmissores especÃficos, resultando em uma resposta anti-inflamatÃria, analgÃsica e reguladora autonÃmica. Neste estudo, objetivou-se avaliar os efeitos da MTF, da Ac e da EAc aplicadas nos acupontos Zusanli (E36) e Sanyjiao (BP6), sobre o estresse oxidativo sistÃmico e local, inflamaÃÃo e glicemia em ratas sadias submetidas a estÃmulo estrogÃnico. No experimento, 42 ratas foram distribuÃdas aleatoriamente em sete grupos. Em 30 ratas (grupos G1C+, G2M, G3Ac, G4EAc2, G5EAc100) administrou-se estrogÃnio (valerato de estradiol, 4mg, dose Ãnica). Os dois grupos restantes serviram como controles negativos (G6M, G7) e nÃo receberam estÃmulo estrogÃnico. ApÃs 60 dias, iniciou-se a segunda fase do estudo, compreendendo um perÃodo de dez dias. A Ac e EAc (2/100Hz), foram aplicadas, sob anestesia, em dias alternados, por 20 minutos, durante nove dias nos grupos G3Ac, G4EAc2, G5EAc100; MTF foi administrada diariamente, por gavagem, durante nove dias aos grupos G2M e G6M. No 10 dia desta fase, todas as ratas foram submetidas ao teste de tolerÃncia oral a glicose,e avaliadas em trÃs ocasiÃes: antes do inicio do teste e apÃs 60/120 minutos; seguiu-se a laparotomia, sob anestesia, para coleta de sangue na artÃria aorta abdominal e exÃrese do Ãtero e ovÃrios para exames a seguir: dosagem de SubstÃncias Reativas ao Ãcido TiobarbitÃrico (TBARs), da Glutationa (GSH) reduzida, da Mieloperoxidase (MPO) e da histopatologia ovariana. Os resultados mostraram um aumento significativo das concentraÃÃes plasmÃticas de GSH nos grupos G3Ac, G4EAc2 e G5EAc100 comparados ao G1 (24,50Â1,59 vs 20,30Â0,43, p<0,05; 30,80Â3,22 e 40,30Â3,48 vs 20,30Â0,43, p<0,0001), respectivamente. Houve aumento significante das concentraÃÃes de GSH no tecido ovariano das ratas tratadas com EAc2/100 (47,00Â17,60 vs 25,70Â2,33, p<0,05 e 63,00Â12,40 vs 25,70Â2,33, p<0,0001). A EAc2/100 promoveu aumento significante nas concentraÃÃes plasmÃticas de TBARS (0,231 0,09 vs 0,054Â0,07, p<0,05 e 0,296Â0,09 vs 0,054Â0,07, p<0,001). Houve reduÃÃo significante na atividade da MPO ovariana nos grupos G4EAc2 e G5EAc100 (0,59Â0,21 vs 1,76Â0,31, p<0,05 e 0,65Â0,05 vs 1,76Â0,31, p<0,0001). A administraÃÃo de MTF nÃo promoveu alteraÃÃes nos marcadores oxidativos ou inflamatÃrios. NÃo mostrou alteraÃÃo da glicemia em nenhum dos grupos estudados. No estudo do nÃmero de folÃculos, corpos lÃteos e cistos foliculares nÃo houve diferenÃa significativa entre todos os grupos estudados, ao exame histopatolÃgico. Conclui-se que a aplicaÃÃo de EAc2/100Hz promove proteÃÃo local e sistÃmica sobre o estresse oxidativo por aumento das concentraÃÃes de GSH, alÃm de reduzir o estado inflamatÃrio no ovÃrio de ratas sadias submetidas a estimulo estrogÃnico.
O desempenho fisiolÃgico da atividade celular requer um equilÃbrio entre a produÃÃo de espÃcies de radicais livres e a sua desativaÃÃo por agentes reguladores e protetores. Quando esse equilÃbrio à quebrado, surge o estresse oxidativo. Diversos estudos experimentais utilizando estrÃgenos para a induÃÃo de distÃrbios ovarianos e metabÃlicos, com destaque para a SÃndrome dos OvÃrios PolicÃsticos (SOP), estÃo disponÃveis na literatura cientÃfica. A Metformina (MTF) à um anti-hiperglicemiante, frequentemente utilizado para tratamento da SOP, permitindo a restauraÃÃo da ciclicidade menstrual, induÃÃo da ovulaÃÃo e o aumento da ocorrÃncia de gestaÃÃo. Na Medicina Tradicional Chinesa, a Acupuntura (Ac) e a Eletroacupuntura (EAc) sÃo utilizadas na promoÃÃo do equilÃbrio orgÃnico, mediante estÃmulo de vias nervosas produtoras de neurotransmissores especÃficos, resultando em uma resposta anti-inflamatÃria, analgÃsica e reguladora autonÃmica. Neste estudo, objetivou-se avaliar os efeitos da MTF, da Ac e da EAc aplicadas nos acupontos Zusanli (E36) e Sanyjiao (BP6), sobre o estresse oxidativo sistÃmico e local, inflamaÃÃo e glicemia em ratas sadias submetidas a estÃmulo estrogÃnico. No experimento, 42 ratas foram distribuÃdas aleatoriamente em sete grupos. Em 30 ratas (grupos G1C+, G2M, G3Ac, G4EAc2, G5EAc100) administrou-se estrogÃnio (valerato de estradiol, 4mg, dose Ãnica). Os dois grupos restantes serviram como controles negativos (G6M, G7) e nÃo receberam estÃmulo estrogÃnico. ApÃs 60 dias, iniciou-se a segunda fase do estudo, compreendendo um perÃodo de dez dias. A Ac e EAc (2/100Hz), foram aplicadas, sob anestesia, em dias alternados, por 20 minutos, durante nove dias nos grupos G3Ac, G4EAc2, G5EAc100; MTF foi administrada diariamente, por gavagem, durante nove dias aos grupos G2M e G6M. No 10 dia desta fase, todas as ratas foram submetidas ao teste de tolerÃncia oral a glicose,e avaliadas em trÃs ocasiÃes: antes do inicio do teste e apÃs 60/120 minutos; seguiu-se a laparotomia, sob anestesia, para coleta de sangue na artÃria aorta abdominal e exÃrese do Ãtero e ovÃrios para exames a seguir: dosagem de SubstÃncias Reativas ao Ãcido TiobarbitÃrico (TBARs), da Glutationa (GSH) reduzida, da Mieloperoxidase (MPO) e da histopatologia ovariana. Os resultados mostraram um aumento significativo das concentraÃÃes plasmÃticas de GSH nos grupos G3Ac, G4EAc2 e G5EAc100 comparados ao G1 (24,50Â1,59 vs 20,30Â0,43, p<0,05; 30,80Â3,22 e 40,30Â3,48 vs 20,30Â0,43, p<0,0001), respectivamente. Houve aumento significante das concentraÃÃes de GSH no tecido ovariano das ratas tratadas com EAc2/100 (47,00Â17,60 vs 25,70Â2,33, p<0,05 e 63,00Â12,40 vs 25,70Â2,33, p<0,0001). A EAc2/100 promoveu aumento significante nas concentraÃÃes plasmÃticas de TBARS (0,231 0,09 vs 0,054Â0,07, p<0,05 e 0,296Â0,09 vs 0,054Â0,07, p<0,001). Houve reduÃÃo significante na atividade da MPO ovariana nos grupos G4EAc2 e G5EAc100 (0,59Â0,21 vs 1,76Â0,31, p<0,05 e 0,65Â0,05 vs 1,76Â0,31, p<0,0001). A administraÃÃo de MTF nÃo promoveu alteraÃÃes nos marcadores oxidativos ou inflamatÃrios. NÃo mostrou alteraÃÃo da glicemia em nenhum dos grupos estudados. No estudo do nÃmero de folÃculos, corpos lÃteos e cistos foliculares nÃo houve diferenÃa significativa entre todos os grupos estudados, ao exame histopatolÃgico. Conclui-se que a aplicaÃÃo de EAc2/100Hz promove proteÃÃo local e sistÃmica sobre o estresse oxidativo por aumento das concentraÃÃes de GSH, alÃm de reduzir o estado inflamatÃrio no ovÃrio de ratas sadias submetidas a estimulo estrogÃnico.
The physiological performance of cellular activity requires a balance between the production of free radicals and their deactivation by regulators and surge protectors. When this balance is broken, the oxidative stress takes place. Several experimental studies using estrogens to induction of ovarian and metabolic disorders, with emphasis on the polycystic ovary syndrome (PCOS), are available in the scientific literature.The Metformin (MTF) is a medication used for diabetic patients, and is often used for treatment of Polycystic Ovary Syndrome (PCOS), allowing restoration of cyclicality, induction of ovulation and menstruation. Acupuncture (Ac) and Electroacupuncture (EAc) are used in Traditional Chinese Medicine for the promotion of organic equilibrium, through stimulation of nerve pathways producing specific neurotransmitters, resulting in an antinflammatory, analgesic and autonomic regulatory response.This study aimed at evaluating the effects of MTF and Ac and EAc, applied on Zusanli (E36) and Sanyjiao (BP6) acupoints on the local and systemic oxidative stress, inflammation and blood glucose levels in healthy rats submitted to estrogenic stimulation. In the experiment, 42 rats were distributed randomly assigned into seven groups. In the experiment, 42 rats were randomly assigned into seven groups. Thirty rats (groups G1C , G2M, G3Ac, G4EAc2, G5EAc100) were administered estrogen (estradiol valerate, 4mg, single dose). The two remaining groups served as negative controls (G6M, G7) and received no estrogenic stimulation. After 60 days, began the second phase of the study, comprising a ten-day period. Ac and EAc (2/100Hz), were applied for 20 minutes, under anesthesia, in alternated days during nine days, to groups G3Ac, G4EAc2, and G5EAc100. MTF was given daily during nine days by gavage to G2M and G6M groups. On the 10th day, all rats were subjected to the oral glucose tolerance test, and evaluated on three occasions: before the beginning of the test and after 60/120 minutes. Next, followed laparotomy, under anesthesia, for collection of blood from the abdominal aorta artery and harvesting of uterus and ovary for examination. Parameters analysed included the Thiobarbituric Acid Reactive Substances (TBARS), reduced Glutathione (GSH), Myeloperoxidase (MPO), and ovarian histopathology. At the end of the experiment plasma concentrations of GSH increased significantly in G3Ac, G4EAc2 and G5EAc100 groups compared to G1 (24.50Â1.59 vs 20.30Â0.43, p<0.05; 30.80Â3.22 and 40.30Â3.48 vs 20.30Â0.43, p<0.0001) respectively. There has been a significant increase in concentrations of GSH in ovarian tissue of rats treated with EAc2/100 (47.00Â17.60 vs 25.70Â2.33, p<.005 and 63.00Â12,40 vs 25,70Â2.33, p<0.0001). There was a significant reduction in ovarian MPO activity in groups G4EAc2 and G5EAc100 (0.59Â0.21 vs 1.76Â0.31, p<0.05 and 0.65Â0.05 vs 1.76Â0.31p<0.001). MTF did not promote changes in oxidative or inflammatory markers. There was no change in blood glucose levels in any of the groups studied. Corpus luteum and follicular cysts number were not different in all groups. It is concluded that EAc2/100Hz treatments promote systemic and local protection on oxidative stress by increasing GSH concentrations and by reducing the inflammatory status in the ovary of healthy rats submitted to estrogenic stimulation.
The physiological performance of cellular activity requires a balance between the production of free radicals and their deactivation by regulators and surge protectors. When this balance is broken, the oxidative stress takes place. Several experimental studies using estrogens to induction of ovarian and metabolic disorders, with emphasis on the polycystic ovary syndrome (PCOS), are available in the scientific literature.The Metformin (MTF) is a medication used for diabetic patients, and is often used for treatment of Polycystic Ovary Syndrome (PCOS), allowing restoration of cyclicality, induction of ovulation and menstruation. Acupuncture (Ac) and Electroacupuncture (EAc) are used in Traditional Chinese Medicine for the promotion of organic equilibrium, through stimulation of nerve pathways producing specific neurotransmitters, resulting in an antinflammatory, analgesic and autonomic regulatory response.This study aimed at evaluating the effects of MTF and Ac and EAc, applied on Zusanli (E36) and Sanyjiao (BP6) acupoints on the local and systemic oxidative stress, inflammation and blood glucose levels in healthy rats submitted to estrogenic stimulation. In the experiment, 42 rats were distributed randomly assigned into seven groups. In the experiment, 42 rats were randomly assigned into seven groups. Thirty rats (groups G1C , G2M, G3Ac, G4EAc2, G5EAc100) were administered estrogen (estradiol valerate, 4mg, single dose). The two remaining groups served as negative controls (G6M, G7) and received no estrogenic stimulation. After 60 days, began the second phase of the study, comprising a ten-day period. Ac and EAc (2/100Hz), were applied for 20 minutes, under anesthesia, in alternated days during nine days, to groups G3Ac, G4EAc2, and G5EAc100. MTF was given daily during nine days by gavage to G2M and G6M groups. On the 10th day, all rats were subjected to the oral glucose tolerance test, and evaluated on three occasions: before the beginning of the test and after 60/120 minutes. Next, followed laparotomy, under anesthesia, for collection of blood from the abdominal aorta artery and harvesting of uterus and ovary for examination. Parameters analysed included the Thiobarbituric Acid Reactive Substances (TBARS), reduced Glutathione (GSH), Myeloperoxidase (MPO), and ovarian histopathology. At the end of the experiment plasma concentrations of GSH increased significantly in G3Ac, G4EAc2 and G5EAc100 groups compared to G1 (24.50Â1.59 vs 20.30Â0.43, p<0.05; 30.80Â3.22 and 40.30Â3.48 vs 20.30Â0.43, p<0.0001) respectively. There has been a significant increase in concentrations of GSH in ovarian tissue of rats treated with EAc2/100 (47.00Â17.60 vs 25.70Â2.33, p<.005 and 63.00Â12,40 vs 25,70Â2.33, p<0.0001). There was a significant reduction in ovarian MPO activity in groups G4EAc2 and G5EAc100 (0.59Â0.21 vs 1.76Â0.31, p<0.05 and 0.65Â0.05 vs 1.76Â0.31p<0.001). MTF did not promote changes in oxidative or inflammatory markers. There was no change in blood glucose levels in any of the groups studied. Corpus luteum and follicular cysts number were not different in all groups. It is concluded that EAc2/100Hz treatments promote systemic and local protection on oxidative stress by increasing GSH concentrations and by reducing the inflammatory status in the ovary of healthy rats submitted to estrogenic stimulation.

O estresse crônico promove diversas alterações no funcionamento de um organismo. O aumento de glicocorticoides pode interferir no estado físico e psicológico de um individuo. Trabalhos recentes correlacionam estresse psicossocial crônico à redução do comprimento dos telômeros de determinadas células. E o estrógeno, além de ser um fator modulador da atividade do sistema de estresse, também pode interferir no comprimento dos telômeros. O objetivo desse trabalho foi verificar se a exposição crônica aos glicocorticóides promove alterações no comprimento dos telômeros de áreas encefálicas envolvidas no controle da atividade do eixo Hipotálamo-Hipófise-Adrenal (HPA) e em respostas comportamentais de ratas, e se o estrógeno pode modular essas alterações. Ratas Wistar ovariectomizadas foram tratadas com cipionato de estradiol (50 ou 100 µg/kg, s.c.) ou óleo, e submetidas à administração de corticosterona 20 mg/Kg ou veículo (salina isotônica 2% Tween 80, s.c.), durante 28 dias. No 25 º dia os animais foram submetidos ao teste do nado forçado, e no 27º dia, ao teste de labirinto em cruz elevado. No dia subsequente ao término do tratamento hormonal, os animais foram eutanasiados para coleta do sangue, cérebro e hipófise. O tratamento com cipionato de estradiol causou: aumento das concentrações plasmáticas de corticosterona e progesterona; redução da expressão de mRNA para CRH, AVP e POMC no PVN; um efeito ansiolítico a avaliado pelo teste do labirinto em cruz elevado; . um efeito depressivo indicado pelo teste de nado forçado; reduziu o tamanho dos na amígdala central e hipocampo dorsal, mas não no PVN. A corticosterona causou: redução da secreção de gonadotrofina; redução da expressão de RNA mensageiro para CRH e POMC e aumento para AVP no PVN; um efeito depressivo indicado pelo teste de nado forçado. O conjunto de resultados mostra que modificação na atividade do eixo HPA e a variação das concentrações plasmáticas de estrógeno podem provocar diversas alterações de ações hormonais, atividades comportamentais e de estrutura do DNA em áreas cerebrais.
Chronic stress promotes several changes in the functioning of an organism. Increased glucocorticoids may interfere with an individual\'s physical and psychological state. Recent works correlate chronic psychosocial stress to the reduction of the telomere length of certain cells. And estrogen, besides being a modulating factor of the activity of the stress system, can also interfere in the length of telomeres. The objective of this study was to verify if chronic exposure to glucocorticoids promotes changes in telomere length of encephalic areas involved in the control of hypothalamic-hypophysis-adrenal (HPA) axis activity and in rat behavioral responses, and whether estrogen can modulate these changes. Ovariectomized Wistar rats were treated with estradiol cypionate (50 or 100 ?g / kg, s.c.) or oil, and given 20 mg / kg corticosterone or vehicle (isotonic saline 2% Tween 80, s.c.) for 28 days. On the 25th day the animals were submitted to the forced swim test, and on the 27th day, the elevated plus maze test. On the day after the end of the hormonal treatment, the animals were euthanized for collection of blood, brain and pituitary gland. Treatment with estradiol cypionate caused: increased corticosterone and progesterone plasma concentrations; reduction of mRNA expression for CRH, AVP and POMC in PVN; an anxiolytic effect as assessed by the elevated plus maze test. A depressive effect indicated by the forced swim test; reduced size in the central amygdala and dorsal hippocampus, but not in PVN. Corticosterone caused: reduction of gonadotrophin secretion; reduction of mRNA expression for CRH and POMC and increase for AVP in PVN; a depressive effect indicated by the forced swim test. The set of results shows that changes in HPA axis activity and variation in plasma estrogen concentrations can lead to several changes in hormonal actions, behavioral activities and DNA structure in brain areas.

Evidências sugerem que as células da glia desempenham um papel importante na sinalização neuronal e na resposta inflamatória no Sistema Nervoso Central (SNC). Respostas inflamatórias crônicas, bem como a ativação da glia estão associadas com doenças neurodegenerativas, como Parkinson e Alzheimer. A inflamação crônica pode ser modulada por altas concentrações de espécies reativas de oxigênio (ERO) que potencializam esse quadro. O estrógeno (E2) é bem conhecido por suas ações neuroprotetoras que podem ser exercidas via receptores clássicos (ESR1, ESR2), não-classicos (GPER-1) ou ainda por sua ação antioxidante, proveniente da alta semelhança com as moléculas dos flavonóides. A ação do E2 no SNC é relevante uma vez que este hormônio está relacionado com a modulação da memória, neurogênese e plasticidade. Este trabalho tem como objetivo investigar o papel protetor do E2 em linhagem de células C6 de glioma de ratos em um modelo de estresse oxidativo que induz morte celular pela exposição a concentrações tóxicas de peróxido de hidrogênio (H2O2). Ensaios de PCR, Western Blot e de imunofluorescência confirmaram a presença e funcionalidade dos receptores ESR1, enquanto ensaios de PCR mostraram a presença do RNAm para o GPER-1 em células C6. Nossos resultados confirmaram que a H2O2 induz morte nas células C6 e o pré-tratamento com E2 (por 24 horas) e G1 (por 20 minutos) diminuiu a toxicidade da H2O2 de maneira dose-dependente, gerando aumento de viabilidade celular. Estes resultados destacam o envolvimento do E2 e seus receptores na prevenção do dano celular em células da glia. Além disso, eles também sugerem que o rápido efeito protetor do E2 parece estar associado com a sinalização rápida do E2 via GPER-1. Por Western blot e RT-PCR avaliamos a participação da via AKT-CREBBDNF frente aos tratamentos com E2, moduladores seletivos de estrógeno (SERMs) e G1, onde observamos que estes são capazes de modular a expressão da proteína AKT e os níveis de RNAm para BDNF.
Evidence suggests that glial cells play an important role in neuronal signaling and inflammatory responses in the central nervous system (CNS). Chronic inflammatory responses, as well as activation of glia, are associated with neurodegenerative disorders such as Parkinson´s and Alzheimer´s diseases. Chronic inflammation can be modulated by high concentrations of reactive oxygen species (ROS) that enhance this process. Estrogen (E2) is well known for its neuroprotective actions that can be performed via classical (ESR1, ESR2) and non-classical receptors (GPER-1) or by its antioxidant action due to its high similarity to flavonoids molecules. E2 action in the CNS is relevant as this hormone is associated to memory modulation, neurogenesis and plasticity. This work has as purpose to investigate the protective role of E2 in rat C6 glioma cell lines in a model of oxidative stress that induces cell death by exposure to toxic concentrations of hydrogen peroxide (H2O2). PCR, Western blot and immunofluorescence assays have confirmed the presence and functionality of the ESR1 receptor, while PCR assay has showed the presence of GPER-1 receptor mRNA in C6 cells. Our results confirmed that H2O2 induces cell death and pre-treatment with E2 (24 hours) and G1 (20 minutes) reduces H2O2 toxicity in a dose-dependent way, leading to increased cell viability. These results highlight the involvement of E2 and its receptors in preventing cell damage in glial cells. Moreover, they also suggest that the prompt E2 protective effect seems to be associated to the fast E2 signaling via GPER-1. We also evaluated the involvement of AKT-CREB-BDNF pathway when C6 cells were treated with E2, selective estrogen modulators (SERMs) and G1 by Western blot and RT-PCR assays, and we could notice that they can modulate the expression of AKT protein and BDNF RNAm levels.

Homocysteine (Hcy) is a sulfur containing amino acid and is a potent neurotoxin. It has been shown that elevated levels of Hcy, termed hyperhomocysteinemia, plays a role in the pathologies of Alzheimer’s disease (AD) and age-related cognitive decline. Hcy is a glutamate agonist, which causes in increase in Ca[superscript (2+)] influx via the activation of NMDA class of excitatory amino acid receptors, which results in neuronal cell death and apoptosis. Estrogen and progesterone are female hormones that are responsible for reproduction and maternal behaviour. However, in the last decade, it is evident that both female hormones have neuroprotective properties in many animal models of neurodegeneration. Collectively, both estrogen and progesterone reduce the consequences of the oxidative stress by enhancing the antioxidant defence mechanisms, reducing excitotoxicity by altering glutamate receptor activity and reducing the damage caused by lipid peroxidation. However, the mechanisms by which estrogen and progesterone provide such neuroprotection probably depend on the type and concentration of hormone present. Moreover, numerous studies have shown that hormone replacement therapy (HRT, estrogen and progestins) or estrogen-only replacement therapy (ERT) may prevent or delay the onset of AD and improve cognition for women with AD. Clinical trials have also shown that women taking HRT may modify the effects of Hcy levels on cognitive functioning. Oxidative stress increases in the aging brain and thus has a powerful effect on enhanced susceptibility to neurodegenerative disease. The detection and measurement of lipid peroxidation and superoxide anion radicals in the brain tissue supports the involvement of free radical reactions in neurotoxicity and in neurodegenerative disorders. The hippocampus is an important region of the brain responsible for the formation of memory. However, agents that induce stress in this area have harmful effects and could lead to dementia. This study aims to investigate and clarify the neuroprotective effects of estrogen and progesterone, using Hcy-induced neurodegenerative models. The initial studies demonstrate that estrogen and progesterone have the ability to scavenge potent free radicals. Histological studies undertaken reveal that both estrogen and progesterone protect against Hcy-induced neuronal cell death. In addition, immunohistochemical investigations show that Hcy-induced apoptosis in the hippocampus can be inhibited by both estrogen and progesterone. However, estrogen also acts at the NMDA receptor as an agonist, while progesterone blocks at the NMDA receptor. These mechanisms reduce the ability of Hcy to cause damage to neurons, since Hcy-induced neurotoxicity is dependent on the overstimulation of the NMDA receptor. SOD and GPx are important enzymatic antioxidants which can react with ROS and neutralize them before these inflict damage in the brain. Hcy can increase oxidative stress by inhibiting expression and function of these antioxidants. However, it has been shown that the antioxidant abilities of both estrogen and progesterone can up-regulate the activities of SOD and GPx. These results provide further evidence that estrogen and progesterone act as antioxidants and are free radical scavengers. The discovery of neuroprotective agents is becoming important as accumulating evidence indicates the protective role of both estrogen and progesterone in Hcy-induced neurodegeneration. Thus further work in clinical trials is needed to examine whether reducing Hcy levels with HRT can become the treatment of neurodegenerative disorders, such as Alzheimer’s disease.

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CNPq
Durante o período reprodutivo,fêmeasproduzemelevados níveis deestrogênios.Os três principais sãoestrona (E1), 17-β-estradiol (E2) e o estriol (E3).O 17-β-estradiol é o estrogênio predominante durante os anos reprodutivos tanto em termos de níveis séricos absolutos como em termos de atividade estrogênica. Inúmeros relatos na literatura postulam que os estrogênios apresentam um importante papel cardioprotetor, e que essa ação protetora pode ocorrer tanto por expressão de genes como também pela ativação de proteínas de cascata de sinalização que culmina no efeito protetor dos estrogênios. Entretanto, o papel dos estrogênios no tecido cerebralcombatendo o estresse oxidativo ainda não é totalmente compreendido. No tronco encefálico, neurônio localizado especificamente na região do bulbo tem um importante papel no controle neuronal do sistema cardiovascular, pois atuam tanto no controle da atividade simpática como também na recepção dos sinais químicos e mecânicos provenientes de barorreceptores e quimiorreceptores. Em adição a essa rede neuronal do controle simpático e da decodificação de sinais aferentes, o tronco encefálico esta sob a influência das ações das espécies reativas de oxigênio-EROS, moléculas essas que tem alta capacidade de induzir a oxidação de lipídios de membrana, proteínas ou mesmo ao DNA, podendo levar a um quadro definido por estresse oxidativo. Hoje em dia, o estresse oxidativo é considerado um dos principais causadores de doenças neurológicas, tais como Parkinson, Alzheimer, Esclerose lateral amiotrófica entre outras. Dessa forma, o objetivo dessarevisãofoiinvestigar os efeitos neuromodulador dosestrogênios na prole fêmeas de mães que foram submetidas adesnutrição proteica no período perinatal (gestação e lactação).
During the reproductive age females significantly produce estrogens.The three major naturally estrogens in women are estrona (E1), 17-β-estradiol (E2) e o estriol (E3). Estradiol is the predominant estrogen during reproductive years both in terms of absolute serum levels as well as in terms of estrogenic activity. Numerous reports in the literature postulates that estrogens play an important cardioprotective role, and that this protective action may occur either by expression of genes but also by activating signaling cascade of proteins that culminates in cardiovascular protection. However, in the brainstem the role of estrogen is still not fully understood. In the brainstem, specifically neuron located in the bulb region, plays an important role in the neuronal control of the cardiovascular system because they act both on the control of sympathetic activity as well as the reception of chemical and mechanical signals. In addition to this neuronal network of sympathetic control and decoding of afferent signals, the brain stem is under the influence of the actions of reactive oxygen species-EROS, these molecules having high ability to induce the oxidation of membrane lipids, proteins or even leading to nuclear DNA to a frame defined by oxidative stress which appears as a major cause of neurological diseases such as Parkinson's, Alzheimer, Amyotrophic lateral sclerosis among others. Thus the aim of the present reviewwasinvestigated the neuromodulator effects of the estrogens on female offsprings from dams that received low protein diet during.

First, this study examined the association of perfluorinated chemicals with 1) cardio-metabolic health outcomes and 2) the association of phthalates with cardiometabolic health outcomes, and 3) cardio-metabolic health outcomes while assessing the possibility of additive interactions between perfluorinated chemicals (PFCs) and phthalates. Second, association with markers of chronic inflammation and oxidative stress were explored. Finally, this study examined the association of these chemicals with estrogenic cancers- Breast cancer, prostate cancer, uterine cancer and ovarian cancer. Using data from the National Health and Nutrition Examination Survey (NHANES), logistic regression models were used to investigate the relationship between PFCs and the cardio-metabolic health outcomes adjusting for covariates. An interaction term between PFCs and phthalates was added to the main effect model to assess the possibility of effect modification. Generalized linear models were used to examine associations between PFCs and inflammatory and oxidative stress markers per unit increase in exposure to PFCs while adjusting for covariates. Binomial logistic regression was used in investigating the association between quartiles of PFCs and presence or absence of cancer while also adjusting for covariates. Discriminant analysis was used to assess the correlation between individual PFCs compounds and individual cancer categories. Perfluorononanoic acid (PFNA) was associated with increased odds of central obesity in females, odds ratio (OR): 1.10; 95% confidence interval (CI): (1.01, 1.21). Perfluorohexane sulfonic acid (PFHS), Perfluorononanoic acid (PFNA), Perfluorooctanoic acid (PFOA), Perfluorooctane sulfonic acid (PFOS), and Perfluorodecanoic acid (PFDE) were all significantly associated with lymphocyte counts. Beta (95% CI); 0.03(0.02,0.05), 0.04(0.02,0.05), 0.05(0.03, 0.07), 0.04(0.03,0.05), 0.03(0.01,0.04) and with serum iron 0.07(0.05,0.09), 0.04(0.02,0.07), 0.10(0.07,0.12), 0.05(0.03,0.07), 0.04(0.02,0.06) and serum albumin 0.02(0.02,0.02), 0.02(0.02,0.03), 0.03(0.03,0.04), 0.02(0.02, 0.023), 0.01 (0.01, 0.05). Only PFHS, PFNA, PFOA and PFOS were associated with serum total bilirubin 0.04(0.03,0.05), 0.02(0.00,0.03), 0.06(0.04,0.08), 0.03(0.02,0.05). PFCs studied were associated with increased odds of breast, prostate, uterine and ovarian cancers, p

Des études épidémiologiques ont démontré que l’exposition aux pesticides tels que le chlordécone augmente le risque du cancer, en particulier de la prostate. Il avait été précédemment montré au laboratoire que le chlordécone possède des propriétés pro-angiogéniques impliquant la libération de NO et la production de VEGF suite à l’activation du récepteur aux oestrogènes de type alpha (ERα). Les processus angiogéniques pouvant impliquer les espèces réactives de l’oxygène (EROs), produites notamment par la mitochondrie, l’objectif de ce travail a été d’évaluer la contribution de la biogenèse mitochondriale et du stress oxydatif dans l’angiogenèse induite par le chlordécone.Les résultats obtenus montrent que la biogenèse mitochondriale n’est pas essentielle pour la réponse angiogénique du chlordécone puisqu’elle n’est retrouvée que pour de forte concentration de chlordécone. Les mécanismes mis en jeu ont été identifiés au niveau des cellules endothéliales humaines. Ils impliquent une régulation spatio temporellede la production des EROs impliquant dans un premier temps la NADPH oxydase, elle même capable de stimuler la production mitochondriale d’EROs via la voie impliquant la NO synthase. Le chlordécone serait par ailleurs capable de favoriser la localisation périnucléaire des EROs afin de favoriser la production de VEGF. L’ensemble de ces effets implique le récepteur aux oestrogènes. Ce travail a donc permis d’identifier les mécanismes cellulaires impliqués dans la modulation de l’angiogenèse par le chlordécone. Ces mécanismes moléculaires pourraient contribuer à identifier de nouvelles cibles permettant de réguler les processus angiogéniques et la tumorigenèse induites par ce toxique
Epidemiological studies report that exposure to pesticides like chlordecone increases risk of prostate cancer and tumorigenesis. We have reported recently that the pro-angiogenic effect of chlordecone involving NO release and VEGF production is mediated through activation of α isoform of the estrogen receptor (ERα). Since mitochondria and ROS have been implicated inthe process of angiogenesis, this study aims to determine the contribution of mitochondrial biogenesisand oxidative stress in chlordecone-induce dangiogenesis. Firstly, our results indicate that mitochondrial biogenesis is not essential for chlordecone angiogenic response. We also identified the molecular mechanism involved; chlordecone induces endothelial cells angiogenesis by a spatiotemporal regulation of ROS production involving NADPH oxidase then mitochondrial O2 -via a NO sensitive pathways through activation of ERα.These findings propose that a molecular mechanism may partly explain the epidemiological evidence implicating chlordecone as risk factor of prostatic cancer

Os efeitos vasculares da associação de estrogênios e testosterona, utilizada para tratamento do distúrbio de desejo sexual hipoativo na pós-menopausa ainda não estão elucidados. O objetivo do trabalho foi avaliar as respostas vasculares ao tratamento de ratas espontaneamente hipertensas ovariectomizadas (SHR-OVX) com o conjugado estrogênio equino (CEE) associado ou não a cipionato de testosterona (CEE+T). O tratamento de SHR-OVX com CEE promove melhora da função endotelial na aorta por mecanismos que envolvem a redução da geração de espécies reativas de oxigênio (EROs) e aumento da expressão proteica de enzimas antioxidantes. O tratamento com CEE+T inibe os efeitos vasculoprotetores do CEE sobre o endotélio, aumentando a geração de EROs e diminuindo a expressão da enzima óxido nítrico sintase. A maior geração de EROs na aorta do grupo CEE+T parece depender da ativação de receptores AT1 de angiotensina II, da maior ação de fator inflamatório o 20-HETE e da ativação da enzima NADPH oxidase.
The vascular effects of estrogens and testosterone association, used for hypoactive sexual desire disorder treatment in postmenopausal women, have not been elucidated. The aim of this study was to evaluate the vascular effects of female ovariectomized (OVX) SHR treatment with conjugated equine estrogen (CEE) associated or not with testosterone cypionate (CEE+T). Our data shows that treatment of OVX-SHR with CEE improved endothelial function reducing reactive oxygen species (ROS) generation and increasing some antioxidant cellular mechanisms. Treatment with CEE+T blunted the vascular effects of CEE, increasing ROS generation and reducing eNOS expression. The increased ROS in CEE+T rats aorta seems to involve in angiotensin II-AT1 activation, 20-HETE action and NADPH oxidase activation.

En aquest treball de tesis doctoral s'estudia el paper de l'estrès oxidatiu tant a la etiologia com a la patofisiologia del dany vascular associat a la malaltia d'Alzheimer. Es demostra la capacitat de les cèl·lules musculars llises vasculars de produir pèptid β-amiloide (Aβ). L'estrès oxidatiu associat a edats avançades, estimula el processament amiloidogènic de l' APP a cèl·lules musculars llises vasculars portant a un augment de producció d' Aβ1-40 i Aβ1-42 contribuint així, a la formació dels depòsits amiloides vasculars. Alhora, els depòsits amiloides vasculars indueixen dany vascular a través d'estrès oxidatiu, a on la nitrotirosinació de proteïnes juga un paper clau en la inactivació d'enzimes essencials per la viabilitat cel·lular. La vitamina E i els estrogens tenen un efecte protector a neurones i cèl·lules musculars llises vasculars mentre que la vitamina E, però no els estrogens, és capaç de protegir les cèl·lules endotelials davant la toxicitat induïda pel pèptid Aβ.
In this thesis we study the effect of oxidative stress in the etiology and pathophysiology of the vascular damage associated to Alzheimer's disease. We demonstrate the production of amyloid-β-peptide (Aβ) by vascular smooth muscle cells. Oxidative stress related to advance ages, induces the amyloidogenic APP cleavage producing an increase of Aβ1-40 and Aβ1-42 by vascular smooth muscle cells, which in tum contribute to vascular amyloid deposits generation. Vascular amyloid deposits induce oxidative stress, in which protein nitrotyrosination plays a key role in essential enzymes inactivation. Vitamin E and estrogens are able to protect neurons and vascular smooth muscle cells while vitamin E, but not estrogens, is able to protect endothelial cells against Aβ-mediated toxicity.

A administração de deidroepiandrosterona (DHEA) tem resultado em efeitos anti-diabetogênicos em animais de experimentação e no homem. Assim, o objetivo desse trabalho foi avaliar o efeito do DHEA sobre a função vascular em aorta e resistência periférica à insulina em roedores fêmeas ovariectomizadas (modelo experimental de menopausa - OVX). O tratamento com DHEA em ratas OVX, embora não levou a nenhuma alteração da composição corporal, induziu a uma redução na pressão arterial sistólica e disatólica, além de uma melhora na função vascular, aumentando a resposta à ACh e reduzindo a resposta à fenilefrina. Isso foi associado a uma redução do estresse oxidativo e inflação na aorta das ratos OVX. Para estudo da resistência à insulina foram utilizadas camundongos fêmeas OVX alimentadas com dieta hiperlipídica. O tratamento com DHEA nesses animais levou a uma redução do percentual de gordura corporal, provavelmente devido a uma redução da ingestão calórica. Também foi observado um aumento da sensibilidade à insulina nos animais tratados com DHEA, associado a uma redução do acúmulo ectópico de lipídios (fígado e músculo). Concluímos que o DHEA pode ser uma possível altenativa de tratamento, ao invés de estradiol, em mulheres na menopausa, já que ele é capaz de melhorar a função vascular e perfil metabólico em modelo experimental de menopausa.
Dehydroepiandrosterone (DHEA) treatment has resulted in anti-diabetogenic effects in both animals and humans. The aim of this study was to evaluate the effect of DHEA on vascular function in the aorta and peripheral insulin resistance in ovariectomized female rodents (experimental model of menopause - OVX). Although DHEA treatment in OVX rats did not lead to any change in body composition, it induced a decrease in blood pressure, and an improvement in vascular function, increasing the ACh response and reduces the response to phenylephrine. This was associated with a reduction in oxidative stress and inflammation in the aorta of OVX rats. For the study of insulin resistance it was used OVX female mice fed with high fat diet. DHEA treatment in these animals led to a reduction in body fat percentage, probably due to a reduction in caloric intake. It was also observed an increase in insulin sensitivity in animals treated with DHEA, associated with a reduction in ectopic fat (liver and muscle) accumulation. We conclude that DHEA may be a possible alternative treatment instead of estradiol, in postmenopausal women, since he is able to improve vascular function and metabolic profile in an experimental model of menopause.

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Among the neurodegenerative diseases those involving the demyelination of the nervous system, such as multiple sclerosis (MS) that affects young and middle-aged adults, have great importance. Thus, the goal of this study was to evaluate 17-β estradiol and resveratrol as promising substances due to their antioxidant and anti-inflammatory actions, in the neuronal and non-neuronal cholinergic system, hematologic and behavioral parameters in ovariectomized rats under or not the demyelination by ethidium bromide (EB). In the article, animals were randomly assigned into three experimental groups of each age. Control groups consisted of adult (sham-A) and middle-aged (sham-MA) female rats, ovariectomized adult (OVX-A) and middle-aged (OVX-MA) rats without estrogen therapy reposition, and ovariectomized adult (OVX+E2-A) and middle-aged (OVX+E2-MA) rats treated with 17-β estradiol for 30 days. After this period, AChE activity and lipid peroxidation were measured in the brain, blood and lymphocytes.The results showed that the acetylcholinesterase (AChE) activity increased in the striatum (ST) of adult ovariectomized animals with and without estrogen replacement and middle-aged animals without replacement, as well as in the hippocampus (HP) of middle-aged animals without hormone replacement. The inhibition of the AChE activity occurred in the ST of adult animals with estrogen replacement, in the cerebral cortex (CC) of adult animals with estrogen replacement, as well as in middle-aged animals with and without hormone replacement. The AChE activity of whole blood increased in adult animals with estrogen supplementation and decreased in middle-aged animals without 17-β estradiol. The AChE activity of lymphocytes was stimulated in adult animals with or without estrogen replacement, and it was inhibited in the middle-aged animals without estrogen replacement. There was an increase in lipid peroxidation in brain structures of all adult ovariectomized animals and cerebellum and cerebral cortex of middle-aged ovariectomized animals. In the manuscripts, the animals were divided into 5 groups to evaluate the demyelination phase and 5 groups to evaluate the remyelination phase. In each phase the groups were: control sham rats; ovariectomized rats, not demyelinated; demyelinated ovariectomized rats; ovariectomized rats, not demyelinated, treated with 17-β estradiol; and demyelinated ovariectomized rats treated with 17-β estradiol. In the manuscript 1, we investigate the effects of 17-β estradiol supplementation under the parameters related to the AChE activity in the brain, total blood and lymphocytes, as well as serum butyrylcholinesterase (BuChE) activity for a period of 7 or 21 days.Ovariectomy associated with EB increased the AChE activity in all structures in demyelination and remyelination phases. Estrogen supplementation stabilized the AChE activity in demyelination and inhibited the enzyme activity in the CC, ST and cerebellum (CE) in the remyelination, besides preventing cognitive impairment induced by ovariectomy. The BuChE activity showed elevation in demyelination and inhibition in remyelination in demyelinated animals treated with 17-β estradiol. The blood AChE activity showed an increase in demyelinated, non-demyelinated with estrogen replacement and demyelinated with estrogen replacement animals in both phases. In the demyelination phase, the AChE activity of lymphocytes showed an increase in the demyelinated group, while other groups have shown inhibition of this enzyme activity. In the manuscript 2, we evaluated the effect of resveratrol on The complete blood count and AChE activity of lymphocytes. The use of resveratrol for seven days decreased the AChE activity in ovariectomized animals and animals with ovariectomy and demyelination, without changing the number of circulating cells, demonstrating that there is no correlation between the circulating lymphocytes and the AChE activity of these cells. Taken together, these results show that 17-β estradiol and resveratrol modulate the AChE activity. The effects of estrogen therapy are dependent on the age and brain structure to be analyzed. Low levels of estrogen are detrimental to the cholinergic system. The damaging effects of ovariectomy can be potentiated in the presence of demyelination, which are generally reversed by the use of 17-β estradiol. This study therefore contributes to a better understanding for the use of estrogen replacement therapy and alternative therapies, such as resveratrol, in menopausal conditions and, especially, neurodegenerative diseases, such as MS, which pursue the process of demyelination. If these results are ratified in humans, these substances can be considered new therapeutic strategies for women.
Dentre as doenças neurodegenerativas, as que causam desmielinização do sistema nervoso central tem grande importância, como a esclerose múltipla (EM) que acomete adultos jovens e de meia-idade. Neste sentido, o 17-β estradiol e o resveratrol surgem como substâncias promissoras devido as suas ações antioxidante, antiinflamatória e neuroprotetora. Assim, o objetivo do presente estudo foi verificar o efeito do 17-β estradiol e do resveratrol nos parâmetros bioquímicos e hematológicos em ratas ovariectomizadas submetidas ao modelo de desmielinização pelo brometo de etídio (BE). No primeiro artigo, os animais foram separados em 3 grupos experimentais para cada idade. Os grupos consistiram de controles adultos (Sham-A) e de meia-idade, ratas ovariectomizadas adultas e de meia-idade e ratas ovariectomizadas com reposição por 30 dias com 17-β estradiol adultas e de meia-idade. Após este período, a atividade da AChE foi mensurada no encéfalo,sangue total e linfócitos, e a peroxidação lipídica foi mensurado apenas no encéfalo. Os resultados obtidos demonstraram que a atividade da acetilcolinesterase (AChE) aumentou no estriado (ST) de ratas adultas ovariectomizadas sem e com reposição estrogênica, e de meia-idade sem reposição. No hipocampo (HP) também foi observado um aumento na atividade desta enzima apenas nas ratas de meia idade sem reposição do hormônio. A inibição na atividade da AChE ocorreu no ST e no córtex cerebral (CC) de ratas adultas com reposição estrogênica e nas ratas de meia-idade com e sem reposição hormonal. A atividade da AChE aumentou no sangue total de ratas adultas com reposição estrogênica e diminuiu nas ratas de meia-idade sem 17-β estradiol. Nos linfócitos foi observado um aumento na atividade da AChE de ratas adultas com ou sem reposição de estrógeno, e inibida no grupo de meia-idade sem reposição estrogênica.Houve um aumento na peroxidação lipídica em todas as estrituras encefálicas dos animais adultos ovariectomizados e córtex cerebral e cerebelo dos animais de meia-idade ovariectomizados.. Nos manuscritos, os animais foram divididos em 5 grupos para avaliar a fase de desmielinização e outros 5 grupos para avaliar a fase de remielinização. Em cada fase, os grupos consistiram de ratas controle; ratas ovariectomizadas; ratas ovariectomizadas e desmielinizadas; ratas ovariectomizadas tratadas com 17-β estradiol (maunscrito 1) ou resveratrol (manuscrito 2); e ratas ovariectomizadas e desmielinizadas tratadas com 17-β estradiol (manuscrito 1) ou resveratrol (manuscrito 2). No manuscrito 1, investigou-se os efeitos do 17-β estradiol sobre os parâmetros relacionados a atividade da AChE encefálica, do sangue total e dos linfócitos, e atividade da butirilcolinesterase (BuChE) por um período de 7 ou 21 dias. Quando a ovariectomia foi associada a desmielinização pelo BE foi observado um aumento na atividade da AChE em todas as estruturas estudadas, na desmielinização e na remielinização A suplementação estrogênica estabilizou a atividade da AChE na desmielinização e inibiu a atividade da enzima no CC, ST e cerebelo (CE) na remielinização, além de conseguir prevenir o prejuízo cognitivo induzido pela ovariectomia. A atividade da butirilcolinesterase (BuChE) aumentou na fase de desmielinização e esteve inibida na fase de remielinização nas ratas tratadas com 17-β estradiol. Já a AChE sanguínea apresentou elevação de sua atividade nas ratas desmielinizadas, não-desmielinizadas com reposição estrogênica e desmielinizadas com reposição estrogênica em ambas as fases. A atividade da AChE dos linfócitos aumentou nas ratas desmielinizadas, enquanto nos demais grupos houve uma inibição na atividade desta enzima na fase de desmielinização. No manuscrito 2, avaliou-se o efeito do resveratrol no hemograma e na atividade da AChE de linfócitos. Apenas o uso do resveratrol por 7 dias diminuiu a atividade da AChE nos linfócitos de ratas submetidas a ovariectomia e nas ratas com ovariectomia e desmielinização, sem alterar o número dos linfócitos na circulação. Assim, os resultados obtidos neste estudo demonstraram que o 17-β estradiol e o resveratrol modulam a atividade da AChE neuronal e não-neuronal. Os efeitos da terapia estrogênica são dependentes da idade e da estrutura encefálica a ser analisada. Além disso, a queda estrogênica é prejudicial ao sistema colinérgico. Os efeitos danosos da ovariectomia podem ser potencializados na presença de desmielinização, sendo estes em grande parte revertidos com o uso do 17-β estradiol. Assim, este estudo colabora para uma melhor compreensão do uso da terapia de reposição estrogênica e terapias alternativas, como o resveratrol, em condições menopáusicas e, principalmente, em doenças neurodegenerativas que cursem com o processo de desmielinização, como a EM. Se ratificados estes resultados na espécie humana, estes compostos poderão ser considerados novas estratégias terapêuticas para as mulheres.

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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
The exposure to stressors produces physiological changes of the organism in order to adapt the individual to the environment. Depending on the type, intensity and duration, stress can affect some cognitive functions, particularly processes of learning and memory. Several studies have also proposed that some level of anxiety would be necessary for memory formation. In this context, memories of previously aversive experiences may determine the manner and intensity with which are expressed fear responses, which explains the great interest in analyzing both anxiety and memory in animals. In addition, males and females demonstrate different reactions in relation to stressful stimuli, showing different levels of anxiety and differences in processing of the acquisition, retention and recall of information. Based on this information, the present study aimed to verify the effect of stress on learning, memory and anxiety behavioral parameters in rats exposed at different types of stressors of long duration (seven consecutive days): restraint (4h/day), overcrowding (18h/day) and social isolation (18h/day) in the different phases of the estrous cycle. Our results showed that the stress induced by restraint and social isolation did not cause changes in the acquisition process, but impaired the recall of memory in rats. Furthermore, it is suggested a protective effect of sex hormones on retrieval of aversive memory, since female rats in proestrus or estrus phase, characterized by high estrogen concentrations, showed no aversive memory deficits. Furthermore, despite the increased plasma levels of corticosterone observed in female rats subjected to restraint stress and social isolation, anxiety levels were unaltered, compared to those various stress conditions. Animal models based on psychological and social stress have been extensively discussed in the literature. Correlate behavioral responses, physiological and psychological have contributed in increasing the understanding of stress-induced psychophysiological disorders
A exposi??o a fatores estressantes promove mudan?as fisiol?gicas adaptativas do organismo ao meio ambiente. Dependendo do tipo, da intensidade e dura??o, o estresse pode afetar algumas fun??es cognitivas, particularmente o processo de aprendizagem e de mem?ria. Alguns estudos tamb?m t?m proposto que a ansiedade, em certa medida, seria necess?ria para que ocorresse a forma??o da mem?ria. Neste contexto, mem?rias de experi?ncias aversivas anteriores podem determinar a maneira e a intensidade com que s?o expressas as respostas de medo, o que justifica o grande interesse em analisar simultaneamente ansiedade e mem?ria em animais. No mais, machos e f?meas apresentam rea??es distintas em rela??o a est?mulos estressores, mostrando diferentes n?veis de ansiedade e diferen?as no processamento da aquisi??o, reten??o e evoca??o de informa??es mnem?nicas. Frente a essas informa??es, o presente estudo teve como objetivo verificar o efeito do estresse em par?metros comportamentais de aprendizagem, mem?ria e ansiedade de ratas submetidas a diferentes tipos de estressores de longa dura??o, (sete dias consecutivos): conten??o (4h/dia), alta densidade populacional (18h/dia) e isolamento social (18h/dia), nas diferentes fases do ciclo estral. Nossos resultados mostraram que o estresse promovido pela conten??o e pelo isolamento social n?o promoveram altera??es no processo de aquisi??o, mas promoveu preju?zos na evoca??o da mem?ria de ratas. Al?m disso, sugere-se um efeito protetor dos horm?nios sexuais sobre a evoca??o da mem?ria aversiva, uma vez que ratas que estavam nas fases proestro ou estro, fase de altas concentra??es plasm?ticas de estr?genos, n?o apresentaram preju?zos na evoca??o dessa mem?ria. No mais, apesar do aumento dos n?veis plasm?ticos de corticosterona observado nas ratas submetidas ao estresse de conten??o e isolamento social, os n?veis de ansiedade permaneceram inalterados frente a essas diferentes condi??es de estresse. Modelos animais baseados em estresse psicol?gico e social t?m sido bastante abordados na literatura. Correlacionar respostas comportamentais, fisiol?gicas e psicol?gicas t?m contribu?do no aumento da compreens?o dos transtornos psicofisiol?gicos envolvidos na resposta de estresse

Endocrine Disrupting Chemicals (EDC) are exogenous agents that mimic endogenous hormone activity in the body. EDC exposure during the critical period of neonatal development can potentially cause life-long neurological, behavioural and physiological disease. This thesis focuses on the EDC Bisphenol A (BPA), a synthetic xenoestrogen widely prevalent in everyday materials that has significant environmental relevance given its ubiquitous presence in humans around the world. The central research question of my thesis is: Does perinatal exposure to BPA affect rat pup development? A rodent model was selected to study the effects of BPA on the adrenal component of the hypothalamic-pituitary-adrenal axis (HPA axis) stress pathway, which has not been extensively studied. Rat dams were divided into five groups (vehicle control (VEH), positive control diethylstilbestrol (DES), BPA 5, BPA 50 and BPA 500 μg/kg bw/day) and dosed daily throughout gestation and for four days of lactation. Rat pups were sacrificed at two time-points at the beginning and the end of the stress hyporesponsive period (SHRP), at postnatal day (PND) 5 and PND 15. Changes in three morphometric parameters (bodyweight, crown-rump (CR) length and anogenital distance (AGD) were assessed based on the factors of Treatment and Sex. Adrenal gland glucocorticoid receptor (GR) and 18SrRNA expression was determined by qPCR in male pups at PND 5 and PND 15. At PND 5, compared to the VEH group, the BPA 50 pups were significantly heavier (ANOVA, Dunnett’s post-hoc) and the DES and BPA 50 pups had significantly longer CR lengths (ANOVA, Dunnetts’ post-hoc). At PND 15, xenoestrogen treatment significantly influenced CR length (ANOVA). At both time-points, males had significantly longer AGD than females, as physiologically expected (ANOVA). Adrenal gland GR expression in male pups was not significantly affected by treatment, but there was an effect of treatment in18SrRNA gene expression at PND 5 (Kruskal-Wallis). Using the Ct method to determine GR and 18SrRNA fold changes, we cautiously suggest that our experimental doses resulted in a non-monotonic dose response to BPA in the PND 5 animals and a monotonic dose response to BPA exposure in the PND 15 animals. This study highly values the importance of investigating the effects of environmentally relevant, low dose BPA exposure during the critical window of development, given the little that is known about potentially permanent alterations to the stress pathway due to exposure during this delicate period of development.

Ainda existe controvérsia se a terapia hormonal estrogênica confere benefício ou dano cardiovascular. O dano potencial causado por doses padrão de estrogênio incluindo doença cardíaca coronariana e trombose venosa pode ser atenuada por uso de doses mais baixas. O objetivo deste estudo foi avaliar o efeito do tratamento com conjugado estrogênio equino, no leito mesentérico venular (LVM) de SHR ovariectomizadas (OVX), com dose padrão (SD) vs dose mínima (LD). Angiotensina II (AngII) foi perfundida de forma concentração-dependente. Hiperreatividade à Ang II, aumento na geração de EROS, redução da atividade da SOD e catalase e da biodisponibilidade do NO foram encontrados em OVX e SD vs controle e LD. Por outro lado, a resposta reduzida à AngII no LVM de ratas LD foi relacionado ao aumento da atividade da eNOS, redução na geração de EROS e aumento da expressão dos receptores AT2,ERα e GPR30. Sugerimos que a dose mínima tem efeito protetor sobre o LVM das OVX e que a dose SD pode aumentar o risco para a doença venular induzindo alterações na reatividade venular.
Controversy still exists whether estrogen hormonal therapy confers cardiovascular benefit or harm. The potential harm caused by standard dosages of estrogen including coronary heart disease and venous thrombosis may be mitigated by use of lower doses. The aim of this study was evaluated the effect of conjugated equine estrogen (CEE) treatment, in isolated mesenteric venular bed (MVB) of ovariectomized SHR (OVX), at standard therapeutic (SD) vs low dose (LD). Angiotensin II (Ang II) was perfused in a concentration-dependent manner. Hyperreactivity to Ang II,augmented ROS generation, reduced SOD, catalase activity and NO availability were found in OVX and SD vs. control and LD. However, the reduced MVB response to Ang II in LD rats was related to increased endothelial NO synthase activity, reduced ROS generation and increased Ang II AT2, ERα and GPR30 receptor expression. We suggest that CEE at a low dose has a protective effect in OVX mesenteric venular bed. The standard dose might increase the risk for venular disease by inducing alterations in venular reactivity.