Secondary amenorrhea, ovulatory disturbances, and luteal phase deficiency occur in normal-weight women with sub-clinical eating disorders. The purpose of this investigation was to examine the influence of Eating Attitudes Test (EAT-26) scores, energy intake, and frequency of activity on ovarian hormone status in normal-weight, college-age women. Fourteen normal-weight female students, ages 19 - 24, who were attempting weight loss and did not currently meet diagnostic criteria for an eating disorder, served as subjects. Food-intake, dieting behavior, and menstrual cycle function were recorded by subjects during a three month period. Biweekly blood samples were assayed for estradiol and progesterone for one menstrual cycle. Mean age, number of years dieting, and BMI were similar between subjects. Five subjects (36%) had progesterone levels indicative of luteal phase deficiency or anovulation. The EAT-26 score was not associated with menstrual cycle dysfunction. Frequency of exercise and serum progesterone concentration were significantly correlated. Subjects who exercised 7+ hours per week had significantly lower peak progesterone values (p<0.03) than subjects who exercised 1 -3 hours per week. Within the group of subjects scoring above 20 on the EAT-26, those who exercised 7+ hours per week had significantly lower peak progesterone values than subjects exercising 1 - 6 hours (p < 0.03). There was a positive correlation (r = 0.384, P = 0.21) between length of luteal phase and daily energy intake, however the relationship was non-significant. Normal-weight, premenopausal women dieting to lose weight experienced menstrual cycle dysfunction in the absence of significant weight loss or diagnosable eating disorder. / Master of Science

Ph. D.

Com o aumento do número de animais inseminados por IATF (inseminação artificial em tempo fixo), a diminuição de custos e o incremento de índices reprodutivos têm sido os objetivos de vários grupos de pesquisa. Nos protocolos de IATF utilizados, empregam-se dispositivos de liberação sustentada de progesterona (P4), que são, em sua maioria, constituídos de um esqueleto de nylon, recoberto com uma camada de silicone com P4 . Visando a diminuição dos custos de produção e impacto ambiental, foi desenvolvido um dispositivo à base de biopolímeros. Neste estudo, foram comparados dispositivos confeccionados com uma blenda constituída de Poli-hidroxi-butirato (PHB) e Poli-&epsion;-caprolactona (PCL), com o Dispositivo Interno Bovino (DIB&reg;), utilizado como controle . No teste in vitro, utilizaram-se dois tipos de dispositivo à base de biopolímeros, com uma área superficial de 147 cm2: DISP8 (46% PHB, 46% PCL e 8% P4; n=4), DISP10 (45% PHB, 45% PCL, 10% P4; n=4) e o DIB&reg; (1 g de P4, área de 120 cm2; n=3). Os testes in vitro foram conduzidos segundo especificações da USP 23, em um dissolutor de comprimidos, empregando-se uma mistura de álcool/água (60/40) como meio de difusão. Amostras do meio foram colhidas aos 2 min., 2, 4, 8, 12, 24, 48, 60, 72, 84 e 96 h. Os teores de P4 foram dosados por espectrofotometria, em 244 nm de comprimento de onda. Realizaram-se as comparações 3 a 3 dos coeficientes angulares das retas obtidas pela regressão das concentrações acumuladas de P4, em função da raiz quadrada do tempo. As médias e respectivos erros-padrão dos coeficientes angulares foram de 677,39 ± 16.13 µg/cm2/t1/2 para o DIB&reg;, 566,17 ± 3.68 µg/cm2/t1/2 para o Disp8 e 774,63 ± 45.26 µg/cm2/t1/2 para o Disp10. Houve diferença entre o DISP8 e o DISP10 (p< 0,05), mas ambos não diferiram do DIB. Para análise das quantidades liberadas por dia de teste in vitro, consideraram-se 4 períodos: 0-24, 24-48, 48-72 e 72-96 h. Houve interação entre tratamento e tempo (p=0,0024). Nas primeiras 24 horas, o DISP8 liberou significativamente menos P4 do que o DISP10 e o DIB&reg;, cujas liberações não diferiram entre si. No intervalo entre 24 e 48h, o DISP 10 liberou significativamente mais P4 do que o DIB&reg;. O DISP8 liberou uma quantidade de P4 intermediária e não se diferenciou significativamente nem do DIB&reg; e nem do DISP10. No intervalo entre 48 e 72h a quantidade de P4 liberada pelo DISP10 foi significativamente maior do que a do DIB&reg; e a do DISP8, que não diferiram entre si. No intervalo entre 72 e 96h, o DISP10 liberou significativamente mais P4 do que o DIB&reg; e o DISP8 liberou uma quantidade intermediária que não diferiu do DIB&reg; nem do DISP10. No teste in vivo, seis vacas mestiças ovariectomizadas receberam DIB (n=4) ou DISP8 (n=8), em um delineamento alternado, com seqüência não balanceada (cross-over), adicionado de medidas repetidas no tempo, referentes aos 16 dias de colheita das amostras de sangue. As amostras foram analisadas por rádio-imuno-ensaio, em fase sólida, utilizando-se &quotkit&quot comercial da DPC (Diagnostics Products Corporation). As concentrações de pico foram atingidas 4 h após a colocação dos dispositivos e este foi o único momento em que as concentrações plasmáticas de P4 diferiram segundo dispositivo (11,45±1,96 vs 9,23±1,15 ng/mL, respectivamente para DIB e DISP8; p= 0,027). No dia 8 do ensaio, as concentrações plasmáticas de P4 proporcionadas pelo DIB e pelo DISP8 foram respectivamente 2,44±0,09 e 1,89±0,13 ng/mL (p=0.58). Ambos dispositivos mantiveram teores de P4 superiores a 1 ng/mL, durante os 16 dias do teste in vivo. Concluiu-se que os dispositivos confeccionados com a blenda dos biopolímeros PHB/PCL, podem liberar P4 de maneira sustentada, tanto quanto os que empregam silicone em sua fabricação. / With the increase in the number of animals inseminated by TAI (timed artificial insemination) the decrease of costs and the improvement of reproductive performance are the goals of several research groups. Progesterone devices which are majority constituted of a nylon skeleton covered with a silicone layer with P4, are used in TAI protocols. Aiming the decrease of the production costs and the environmental impact, was a new device developed with biopolymers matrix. In this study, were compared a blend of Poli-hidroxi-butirate (PHB) and poli-?-caprolactone (PCL) device with the Bovine Internal Device (DIB&reg;). In the in vitro test, two kinds of the new device with a superficial area of 147 cm2: DISP8 (46% PHB, 46% PCL and 8% P4; n=4), DISP10 (45% PHB, 45% PCL, 10% P4; n=4) and DIB&reg; (1 g of P4, area of 120 cm2; n=3). The in vitro tests were led following USP 23 specifications in a drug dissolutor in alcohol/water (60/40) solution as a diffusion medium. Samples were collected at 2 min., 2, 4, 8, 12, 24, 48, 60, 72, 84 and 96 hours. Progesterone concentrations were estimated by spectrophotometry at UV 244 nm wavelenght. Comparisons 3 by 3 of the angular coefficients of the straight lines obtained by the regression of the accumulated P4 concentrations in function of the square root of time were performed. The averages and respective standard-errors of the angular coefficients were 677,39 ± 16.13 µg/cm2/t1/2 to DIB&reg;, 566,17 ± 3.68 µg/cm2/t1/2 to Disp8 and 774,63 ± 45.26 µg/cm2/t1/2 to Disp10. Difference were observed between DISP8 and DISP10 (p< 0.05) but both did not differ to DIB&reg;. Four periods were considered for analysis of the amounts released per day of in vitro test: 0-24, 24-48, 48-72 and 72-96 hours. Interaction between treatment and time was observed (p=0.0024). In the first 24 hours DISP8 released significantly less P4 than DISP10 and DIB&reg; but the lathers did not differ from each other. In the interval between 24 and 48 hours DISP10 released significantly more P4 than DIB&reg;. The device DISP8 released an intermediary concentration of P4 and was similar to DIB&reg; and to DISP10. In the interval between 48 and 72 hours the progesterone concentration released by DISP10 was significantly higher than DIB&reg; and DISP8 but lathers did not differ from each other. In the interval between 72 and 96 hours DISP10 released significantly more P4 than DIB&reg; while DISP8 released an intermediary amount which did not differ to DIB&reg; or to DISP10. In the test in vivo test, six ovariectomized beef cows received the devices DIB&reg; (n=4) or DISP8 (n=8) in an alternated delineation in a nom balanced sequence (cross-over) added of repeated measures in time, related to the 16 days of blood samples collects. Progesterone concentration from these samples were measured by radioimmunoassay in solid phase using the commercial kit from DPC (Diagnostics Products Corporation). The peak of the progesterone concentrations were observed 4 hours after the devices insertion and this was the unique moment in which plasmatic progesterone concentrations differed depending on device (11,45 ± 1,96 vs 9,23 ± 1,15 ng/mL, respectively for DIB and DISP8; p= 0,027). After 8 days from the device insertion plasmatic progesterone concentrations provided by DIB and DISP8 were respectively 2,44 ± 0,09 and 1,89 ± 0,13 ng/mL (p=0.58). Both devices kept the progesterone concentration higher than 1 ng/mL during the 16 days of the in vivo test. In conclusion, the devices made with biopolymers blends of PHB/PCL can release sustained P4 comparable with silicone matrix.

A proliferação celular mediada pela progesterona (P4) é essencial para a funcão uterina. Dessa forma, alterações nesse processo podem comprometer a reprodução. O diabetes do tipo 1 (DM1) está associado a diversos distúrbios reprodutivos. No entanto, o impacto do DM1 sobre a ação da P4 no ambiente uterino ainda não é conhecido. Para isso, utilizamos fêmeas de camundongo DM1 induzidas por aloxana, submetidas à ovarectomia (OVX) e reposição por P4. Verificamos por meio de histomorfometria e imunohistoquímica (PCNA) uma diminuição da área de estroma uterino e do índice de proliferação. As quantificações proteícas por Western blot monstraram um aumento do PR-A nas fêmeas diabéticas OVX e nas tratadas pela P4. Ressalta-se que as fêmeas DM1 tratados pela P4 não apresentaram a mesma expressão do RNAm para o fator de crescimento Hoxa-10. Houve também um aumento do RNAm da p27 nas fêmeas DM1 não tratadas, visto por qPCR. Nossos resultados demonstraram que o DM1 interfere negativamente na resposta proliferativa promovida pela P4. Contribuindo para compreensão dos mecanismos biológicos pelos quais o diabetes compromete as funções reprodutivas. / Progesterone (P4)-mediated cell proliferation is essential for uterine function. Therefore, alteration in this process could compromise reproduction. The type 1 diabetes (DM1) relates to several reproductive disturbs. However, the impact of DM1 on the P4 function is still not elucidated. Thus, we used alloxan-induced diabetic mice females subjected to ovariectomy and hormonal replacement therapy with P4. Histomorphometrical and immunohistochemistry to PCNA approaches showed a decrease of the uterine stromal area and the cell proliferation index. Protein quantification by Western blot showed increased levels of PR-A in both ovariectomized and P4-treated diabetic females. Importantly, P4 did not recovered the mRNA expression to the Hoxa-10 transcription factor in diabetic females. Additionally, qPCR analysis revealed increased level of p27 mRNA in diabetic females non-treated with P4. Together these results show that DM1 has a negative action on the P4-mediated cell proliferative response. These are new and important results to a better understand of the biological mechanisms by which diabetes affects the reproductive functions.

Source: Dissertation Abstracts International, Volume: 69-10, Section: B, page: 6009. Adviser: Dorothy K. Waller. Includes bibliographical references.

Chez les vertébrés, la progestérone (P4) est un progestatif endogène agissant via les récepteurs nucléaires et membranaires de la progestérone pour médier des processus clés du développement et de la reproduction. De nombreuses molécules sont conçues pour mimer l’action de la P4. Ces progestatifs synthétiques et la P4 sont très utilisés en tant que substances pharmaceutiques et certains sont retrouvées dans l’environnement aquatique, posant un risque pour les organismes. Cependant, les informations sont insuffisantes pour évaluer les dangers et les risques de ces substances pour l’environnement. Dans ce travail de thèse, les mécanismes d’action et les effets biologiques des progestatifs sur le poisson zèbre ont été étudiés grâce à une combinaison d’outils in vitro et in vivo de type gène-rapporteur basés sur le mécanisme d’action des perturbateurs endocriniens. Nous avons caractérisé le profil toxicologique complexe de 26 progestatifs vis-à-vis de différents récepteurs nucléaires stéroïdiens humain et poisson zèbre et vis-à-vis de l’expression tissu-spécifique de gènes de la stéroïdogenèse (cyp19a1b dans le cerveau et cyp11c1 dans les interrénales). Nos résultats montrent que certains progestatifs peuvent perturber différentes voies de signalisation chez les larves en développement au niveau moléculaire, cellulaire et tissulaire ainsi qu’au niveau physiologique. Dans l’ensemble, les résultats de cette thèse permettent une meilleure caractérisation des dangers des progestatifs sur différentes cibles endocriniennes. / Among vertebrates, progesterone (P4) is an endogenous progestin acting through the nuclear and molecular progesterone receptor to mediate key processes of development and reproduction. Many molecules are designed to mimic the action of P4. These synthetic progestins and P4 are widely used as pharmaceuticals and some of them are found in this aquatic environment, thus posing risks to aquatic species. However, information is lacking to evaluate the dangers and risks of these substances for the environment. This thesis studied the mechanisms of action and the effects of progestins on zebrafish, using a combination of reporter-gene in vitro and in vivo tools based on the mechanism of action of endocrine disruptors. We characterized the toxicological profile of 26 progestins towards different human and zebrafish nuclear steroid receptors and towards the tissue-specific expression of steroidogenic genes (cyp19a1b in the brain and cyp11c1 in the interrenal cells). Our results show that some progestins can disrupt different signaling pathways in developing larvae at the molecular level, cellular and tissular level, and physiological level. Overall, the results of this thesis allow for a better characterization of the dangers of progestins on several endocrine targets.

A proliferação celular mediada pela progesterona (P4) é essencial para a funcão uterina. Dessa forma, alterações nesse processo podem comprometer a reprodução. O diabetes do tipo 1 (DM1) está associado a diversos distúrbios reprodutivos. No entanto, o impacto do DM1 sobre a ação da P4 no ambiente uterino ainda não é conhecido. Para isso, utilizamos fêmeas de camundongo DM1 induzidas por aloxana, submetidas à ovarectomia (OVX) e reposição por P4. Verificamos por meio de histomorfometria e imunohistoquímica (PCNA) uma diminuição da área de estroma uterino e do índice de proliferação. As quantificações proteícas por Western blot monstraram um aumento do PR-A nas fêmeas diabéticas OVX e nas tratadas pela P4. Ressalta-se que as fêmeas DM1 tratados pela P4 não apresentaram a mesma expressão do RNAm para o fator de crescimento Hoxa-10. Houve também um aumento do RNAm da p27 nas fêmeas DM1 não tratadas, visto por qPCR. Nossos resultados demonstraram que o DM1 interfere negativamente na resposta proliferativa promovida pela P4. Contribuindo para compreensão dos mecanismos biológicos pelos quais o diabetes compromete as funções reprodutivas. / Progesterone (P4)-mediated cell proliferation is essential for uterine function. Therefore, alteration in this process could compromise reproduction. The type 1 diabetes (DM1) relates to several reproductive disturbs. However, the impact of DM1 on the P4 function is still not elucidated. Thus, we used alloxan-induced diabetic mice females subjected to ovariectomy and hormonal replacement therapy with P4. Histomorphometrical and immunohistochemistry to PCNA approaches showed a decrease of the uterine stromal area and the cell proliferation index. Protein quantification by Western blot showed increased levels of PR-A in both ovariectomized and P4-treated diabetic females. Importantly, P4 did not recovered the mRNA expression to the Hoxa-10 transcription factor in diabetic females. Additionally, qPCR analysis revealed increased level of p27 mRNA in diabetic females non-treated with P4. Together these results show that DM1 has a negative action on the P4-mediated cell proliferative response. These are new and important results to a better understand of the biological mechanisms by which diabetes affects the reproductive functions.

L’accident vasculaire cérébral (AVC) déclenche une cascade de changements qui conduisent à la mort cellulaire mais aussi des processus endogènes de protection en réponse à l'ischémie. La compréhension de ces processus est très importante pour le développement d’agents neuro-protecteurs potentiels qui peuvent être seulement des amplificateurs des processus endogènes. Le traitement par la progestérone est neuro-protecteur dans des modèles expérimentaux d’occlusion de l'artère cérébrale moyenne (MCAO). Cependant, des niveaux endogènes significatifs de progestérone sont mesurables dans le cerveau de souris mâles et femelles.Le but de notre travail était d'étudier: 1) les effets de l’ischémie sur les niveaux endogènes des stéroïdes et le rôle des récepteurs de la progestérone (PR) à la phase aiguë après ischémie chez les souris jeunes adultes et âgées des deux sexes; 2) la base cellulaire de la neuroprotection par la progestérone après ischémie et le rôle de PR neural. Nous avons utilisé un modèle d’ischémie expérimentale (MCAO); une lignée transgénique de souris (PRNesCre) dans laquelle l’expression de PR a été sélectivement invalidée dans les cellules neurales; la chromatographie en phase gazeuse-spectrométrie de masse en tandem (GC-MS/MS); et des analyses histologiques, comportementales, et d’immunofluorescence.Dans la première partie, nous avons montré que dans le cerveau de souris mâles la progestérone est principalement convertie en 5a-dihydroprogestérone (5a-DHP), qui est un agoniste naturel de PR. Après MCAO, les niveaux de progestérone et de 5a-DHP cérébrales augment chez les mâles, mais pas chez les femelles. En revanche, les femelles peuvent utiliser l’inter-conversion de la 20a-dihydroprogestérone et de la progestérone pour réguler la disponibilité des pregnanes actifs au niveau de PR. De plus, les souris PRNesCre, mâles et femelles jeunes adultes et âgées, ont des infarctus plus grands et des déficits sensori-moteurs plus importants ainsi qu’une diminution de la densité des neurones et de la microglie activée comparativement aux souris témoins PRloxP/loxP. En outre, nos résultats ont révélé des différences liées au sexe chez les souris jeunes, mais pas chez les souris âgées. Dans la deuxième partie de l'étude, nous avons montré que, chez les souris mâles PRloxP/loxP, le traitement par la progestérone améliore la récupération fonctionnelle et réduit le volume de l'infarctus. Dans le péri-infarctus, la progestérone augmente la densité des neurones, des oligodendrocytes et de leurs précurseurs, et diminue la densité des astrocytes et de la microglie activée, et l'expression de l’aquaporine 4. Ces effets de la progestérone n’ont pas été observés chez les souris PRNesCre.Nos résultats montrent 1) l'importance des pregnanes endogènes et du PR neural pour la protection cérébrale à la phase aiguë précoce après une ischémie; 2) que le traitement par la progestérone chez les souris mâles après ischémie a des effets neuro-protecteurs, pro-myélinisants et anti-inflammatoires et que PR neural est requis pour la médiation de ces effets. Ces données suggèrent fortement que les ligands de PR ou des agents ciblant leur signalisation en aval pourraient être développés pour la neuro-protection après un AVC. / Ischemic stroke initiates a cascade of changes that lead to cell death and also coordinates endogenous processes that counteract the nocuous consequences of ischemia. Understanding these processes is very important for the development of potential neuroprotectants which can be just boosters of endogenous processes. Treatment with exogenous progesterone is neuroprotective after middle cerebral artery occlusion (MCAO). However, the male and female brains contain significant amounts of endogenous progesterone.The aim of our work was to study: 1) the effects of MCAO on the endogenous levels of steroids and the role of neural progesterone receptors (PR) at the acute phase after stoke in young and aging mice of both sexes; 2) the cellular basis of the neuroprotection by progesterone following stroke and the role of neural PR. We used an in vivo model of MCAO; a transgenic mice line (PRNesCre) selectively lacking the expression of PR in neural cells; gas chromatography-tandem mass spectrometry (GC-MS/MS); and histological, behavioral, and immunofluorescence analyses.In the first part of the study, we showed that in the male mouse brain, progesterone is mainly converted to 5a-dihydroprogesterone (5a-DHP), which is a natural PR agonist ligand. After MCAO, brain levels of progesterone and 5a-DHP are rapidly upregulated in males but not in females. In contrast, females may use the interconversion of 20a-dihydroprogesterone and progesterone for regulating the availability of PR-active pregnanes. Moreover, young and aging male and female PRNesCre mice exhibited increased infarcts, severe sensorimotor deficits, and decreased densities of neurons and microglia comparatively to age-matched control mice PRloxP/loxP. In addition, our results revealed sex differences in stroke outcomes in young but not in aging mice. In the second part of the study, we showed that, in male PRloxP/loxP mice, progesterone improved sensorimotor outcomes and reduced infarct volumes. In the peri-infarct, progesterone increased the densities of neurons, oligodendrocytes and their precursors, decreased the densities of activated astrocytes and microglia, and the expression of the aquaporin 4. These beneficial effects of progesterone were not observed in PRNesCre mice.Our findings 1) uncover the importance of endogenous pregnanes and neural PR for the cerebroprotection at the early acute phase after stroke; 2) show that progesterone treatment in male mice has neuro-protectant, pro-myelinating and anti-inflammatory effects after MCAO and that neural PR is required for the mediation of these effects. These data strongly suggest that ligands of PR or agents targeting their downstream signaling could be developed for neuroprotection after stroke.

Thesis (M.Sc.)--Memorial University of Newfoundland, Faculty of Medicine, 1999. / Bibliography: leaves 118-138.

A perimenopausa representa a transição da vida reprodutiva para não reprodutiva. É geralmente caracterizada por alterações neuroendócrinas, metabólicas e comportamentais, um possível resultado da depleção folicular ovariana e consequente redução do número de folículos ovarianos. É o período em que as mulheres podem apresentar maior susceptibilidade a manifestar transtornos afetivos e de ansiedade. A exposição de roedores ao resíduo químico 4-diepóxido de vinilciclohexeno (VCD) é um modelo bem estabelecido para estudos sobre perimenopausa, pois o VCD acelera o processo natural de atresia folicular. Embora as concentrações plasmáticas de estradiol estejam normais ou elevadas durante a perimenopausa, a terapia com estradiol pode ser benéfica para mulheres sintomáticas na perimenopausa. Portanto, o objetivo do presente trabalho foi investigar se a depleção folicular gradativa acelerada pelo VCD resulta em alterações na neuroquímica de ratas fêmeas em núcleos cerebrais que controlam o humor, além de avaliar se o estradiol seria capaz de reverter as possíveis alterações. Ratas da linhagem Wistar (28 dias pós-natal) receberam diariamente, durante 15 dias consecutivos, injeções subcutâneas de VCD (160 mg / kg) ou óleo de milho (O). Aproximadamente 55 dias após a primeira injeção, cápsulas de silastic contendo 17?-estradiol (E) ou O foram inseridas subcutaneamente (Grupos O+O; VCD+O; VCD+E). Cerca de 21 dias após o implante das cápsulas, as ratas dos grupos O+O e VCD+O foram decapitadas na manhã do diestro, enquanto que as do grupo VCD+E foram decapitadas exatamente 21 dias após o implante das cápsulas contendo estradiol, entre 0900 h e 1100 h. O sangue foi colhido para avaliação das concentrações plasmáticas de estradiol e progesterona por radioimunoensaio (RIE). Os cérebros foram removidos para microdissecção do hipocampo, amígdala, Locus coeruleus (LC) e Núcleo Dorsal da Rafe (NDR), para posterior análise dos níveis de RNAm para os receptores de progesterona (PR) e estradiol do tipo beta (ER?) por meio de RT/PCR. Este experimento foi replicado para remoção do hipocampo e amígdala para dosagem dos conteúdos de noradrenalina (NA) e serotonina (5-HT) por meio de cromatografia líquida de alta performance, seguida de detecção eletroquímica (HPLC/ED). Outro conjunto de ratas submetidas às mesmas condições10 experimentais foi perfundido para imunohistoquímica para TPH no NDR e TH no LC. Como esperado, na periestropausa (grupo VCD+O) as concentrações plasmáticas de estradiol não foram diferentes daquelas das ratas controles (O+O). As concentrações plasmáticas de progesterona na periestropausa foram menores que as do grupo controle, o que foi revertido pelo estradiol. No LC, a expressão de PR na periestropausa foi igual à das ratas controles, enquanto a expressão do ER? foi menor; a terapia com estradiol não modificou a expressão de nenhum destes receptores. A densidade de neurônios noradrenérgicos (TH+) no LC não foi alterada nem pela depleção folicular nem pela terapia estrogênica. Na periestropausa, o conteúdo de NA foi menor na amígdala, mas não no hipocampo, e o estradiol não alterou este conteúdo em nenhuma das áreas. No NDR, a expressão de PR e de ER? nas ratas na periestropausa foi menor que nas ratas controles; o estradiol preveniu o declínio da expressão de ER?, mas não de PR. O NDR foi analisado separadamente por toda a extensão rostro-caudal em 3 níveis anatômicos: rostral, médio e caudal, cada um dividido em 3 sub-regiões: lateral, dorsal e ventral. O número de neurônios serotonérgicos (TPH+) no NDR foi menor na periestropausa, e o estradiol foi capaz de reverter esse efeito, atuando principalmente na região caudal. A expressão gênica de PR não foi alterada nem pela depleção folicular nem pela terapia estrogênica tanto na amígdala como no hipocampo. A expressão de ER? também não foi diferente na periestropausa, quando comparada ao grupo controle, mas o estradiol aumentou esta expressão no hipocampo. Tanto na amígdala como no hipocampo houve redução no conteúdo de 5-HT na periestropausa e estradiol foi capaz de reestabelecer os níveis deste neurotransmissor aos valores controles apenas no hipocampo. Estes dados elucidam, pelo menos em parte os mecanismos do efeito positivo da terapia estrogênica nos sintomas de mulheres normoestrogênicas na perimenopausa. Estes efeitos parecem não envolver de forma importante o sistema noradrenérgico central, mas resultar do aumento da biossíntese de progesterona periférica em associação com a regulação positiva de ER? no NDR e hipocampo, que parece potencializar a via serotonérgica NDR/HPC. Portanto, o desenvolvimento de novas terapias que ativem os ER? pode ser uma alternativa para obter os efeitos positivos da ação do estradiol, eliminando os efeitos colaterais das terapias de estradiol que normalmente resultam da ativação do ER?. / Perimenopause represents the transition from reproductive to non-reproductive life. It is usually characterized by neuroendocrine, metabolic and behavioural changes, which result from a follicular depletion and reduced number of ovarian follicles. During this period, women are more likely to express mood disorders and anxiety. The exposure of animals to diepoxide 4-vinylcyclohexene (VCD) is a well-established experimental model for perimenopause studies, as VCD induces loss of ovarian small follicles (primary and primordial) in mice and rats by accelerating the natural process of atresia. Although estrogens levels are normal or even high during perimenopause, estrogen therapy can be beneficial for symptomatic perimenopausal women. The aim of this study was to investigate whether gradual follicular depletion induced by VCD results in changes in the neurochemistry of female rats in brain nuclei that control mood and the role of estradiol on these changes. Female rats (28 days) were daily injected with VCD or corn oil (O) for 15 days. Around 55 days after the first injection, pellets of 17?-estradiol (E) or O were inserted s.c (Groups O+O; VCD+O; VCD+E). Around 21 days after, rats O+O and VCD+O were decapitated between 0900 h and 1100 of diestrus while rats VCD+E were decapitated exactly 21 days after the onset of E therapy. Another set of rats followed the same experimental design and were perfused for TH and TPH immunohistochemistry in Locus coeruleus (LC) and Dorsal Raphe Nuclei (DRN), respectively. Blood was collected for estradiol and progesterone measurement by radioimmunoassay (RIA). The brains were removed from decapitated rats to punch out LC, DRN, hippocampus and amygdala to analyse the expression of mRNA for ER? and PR by RT/PCR. This experiment was replicated to punch out the hippocampus and amygdala for the determination of noradrenaline (NE) and serotonin (5-HT) contents by High Performance Liquid Chromatography, followed by Electrochemical Detection (HPLC/ED). As expected, plasma concentrations of estradiol were not different from those of control rats (O + O). Plasma concentrations of progesterone in the periestropause were lower than those in the control group, which was reversed by estradiol. In the LC, the PR expression in the periestropause was similar to that of the control rats, whereas the ER? expression was lower; estradiol therapy did not modify the expression of any of these receptors. The12 density of noradrenergic (TH +) neurons in LC was not altered by either follicular depletion or estrogen therapy. In periestropause, NA content was lower in the amygdala, but not in the hippocampus, and estradiol did not alter this content in any of the areas. In NDR, the expression of PR and ER? in periestropausal rats was lower than in controls; estradiol prevented the decrease of ER? expression, but not PR. The NDR was analyzed separately for the entire rostrocaudal axis in three anatomical levels: rostral, middle and caudal, each divided into three sub-regions: lateral, dorsal and ventral. The number of serotonergic neurons (TPH +) in NDR was lower in the periestropause, and estradiol was able to reverse this effect, acting mainly in the caudal region. PR gene expression was not altered by either follicular depletion or estrogen therapy in either the amygdala or the hippocampus. ER? expression was also no different in periestropause compared to the control group, but estradiol increased this expression in the hippocampus. Both in the amygdala and in the hippocampus there was a reduction in 5-HT content in the periestropause, and estradiol was able to reestablish the levels of this neurotransmitter at the control values only in the hippocampus. These data elucidate, at least in part, the mechanisms of the positive effect of estrogen therapy on the symptoms of normoestrogenic women in perimenopause. These effects do not appear to significantly involve the central noradrenergic system but result from increased peripheral progesterone biosynthesis in association with positive regulation of ER? in the NDR and hippocampus, which appears to potentiate the serotonergic NDR/HPC pathway. Therefore, the development of new therapies that activate ER? may be an alternative to obtain the positive effects of the estradiol action, eliminating the side effects of the estradiol therapies that normally result from the activation of ER?.