Navegando por Palavras-chave "Sex hormones"
Agora exibindo 1 - 4 de 4
Resultados por página
Opções de Ordenação
- ItemAcesso aberto (Open Access)Estudos de aspectos metabólicos, neuroquímicos e comportamentais de ratas alimentadas com dieta hiperlipídica: o papel do ciclo estral(Universidade Federal de São Paulo, 2021-09-30) Silva, Sara Pereira da [UNIFESP]; Ribeiro, Alessandra Mussi [UNIFESP]; Estadella, Debora [UNIFESP]; http://lattes.cnpq.br/5715718187140258; http://lattes.cnpq.br/7373640456805525; http://lattes.cnpq.br/3775172431639017; Universidade Federal de São Paulo (UNIFESP)Atualmente a incidência de obesidade no mundo tem aumentado consideravelmente. O consumo de dietas hiperlipídicas, dentre elas a dieta do tipo cafeteria (CAF), pode levar ao desenvolvimento de obesidade e promover diversas complicações metabólicas, neuroinflamação e alterações comportamentais. Os mecanismos relacionados ao consumo de dieta CAF e ao desenvolvimento de alterações ainda não são totalmente conhecidos, mas há uma correlação positiva entre a ativação da sinalização pró-inflamatória e do estresse oxidativo (EO) em diversos tecidos, incluindo o encéfalo, e o consequente desenvolvimento de alterações comportamentais. Ainda, é importante considerar que as flutuações dos níveis de hormônios sexuais ao longo do ciclo estral podem influenciar positiva ou negativamente o comportamento. Neste contexto, o presente estudo teve por objetivo investigar os efeitos do tratamento com CAF em ratas quando avaliadas em relação a parâmetros comportamentais, emocionais e mnemônicos. Para isso, ratas Wistar (12 semanas de idade, pesando 200-300 g) foram distribuídas em dois grupos e alimentadas com dieta comercial (DC) ou CAF durante 32 dias. A fase do ciclo estral foi monitorada durante todo o protocolo experimental. A partir do 28° dia foram realizados os testes de preferência por sacarose, campo aberto, reconhecimento de objeto novo, alternação espontânea, labirinto em cruz elevado (LCE) e esquiva discriminativa em labirinto em cruz elevado (EDL). No 33° dia os animais foram eutanasiados, amostras de sangue foram coletadas para análise de parâmetros metabólicos e o encéfalo foi removido para posterior avaliação de marcadores inflamatórios, além da avaliação da imunorreatividade do fator neurotrófico derivado do encéfalo (BDNF) e da tirosina hidroxilase (TH). Os resultados mostraram que ratas alimentadas com dieta CAF quando comparadas a ratas DC apresentam: (1) maior ganho de massa corporal; (2) menor consumo de sacarose na fase diestro; (3) quando em diestro e metaestro mostram prejuízo na memória de reconhecimento de objetos; (4) pior desempenho em tarefa de memória operacional; (5) menor densidade ótica relativa para BDNF hipocampal. No entanto, (6) não foram observadas diferenças em relação a atividade exploratória e ansiedade no CA e LCE respectivamente. De forma geral, podemos sugerir que a ingestão de dieta CAF por ratas pode provocar déficits dependentes da fase de ciclo estral.
- ItemSomente MetadadadosGender-related differences in circadian rhythm of rat plasma acetyl- and butyrylcholinesterase: Effects of sex hormone withdrawal(Elsevier B.V., 2010-06-07) Alves-Amaral, Gracielle [UNIFESP]; Pires-Oliveira, Marcelo [UNIFESP]; Andrade-Lopes, Ana Luiza [UNIFESP]; Chiavegatti, Tiago [UNIFESP]; Godinho, Rosely Oliveira [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The role of acetylcholinesterase (AChE) in the termination of the cholinergic response through acetylcholine (ACh) hydrolysis and the involvement of plasma butyrylcholinesterase (BuChE), mainly of hepatic origin, in the metabolism of xenobiotics with ester bonds is well known. Besides, BuChE has a crucial role in ACh hydrolysis, especially when selective anticholinesterases inhibit AChE. Herein, we analyzed the gender-related differences and the circadian changes of rat plasma cholinesterases. Plasma and liver cholinesterase activities were evaluated in control or 2-30-day castrated adult male and female rats. Plasma and liver AChE activities did not differ between genders and were not influenced by sex hormone deprivation. BuChE plasma activity was 7 times greater in female, reflecting gender differences in liver enzyme expression. Castration increased liver and plasma BuChE activity in male, while reduced it in female, abolishing gender differences in enzyme activity. Interestingly, female AChE and BuChE plasma activities varied throughout the day, reaching values 27% and 42% lower, respectively, between 2 p.m. and 6 p.m. when compared to the morning peaks at 8 a.m. Castration attenuated daily female BuChE oscillation. On the other hand, male plasma enzymes remained constant throughout the day. in summary, our results show that liver and plasma BuChE, but not AChE, expression is influenced by sex hormones, leading to high levels of blood BuChE in females. the fluctuation of female plasma BuChE during the day should be taken into account to adjust the bioavailability and the therapeutic effects of cholinesterase inhibitors used in cholinergic-based conditions such Alzheimer's disease. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
- ItemSomente MetadadadosPuberty and growth rate in thoroughbred fillies(Elsevier B.V., 1997-09-01) Nogueira, Guilherme de Paula; Barnabe, Renato Campanarut; Verreschi, Ieda Therezinha do Nascimento [UNIFESP]; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)We measured progesterone and estradiol levels from birth to the beginning of adult life in 10 Thoroughbred fillies from the Equilia Stud Farm in Avare SP, Brasil. the animals were measured and weighed monthly for the determination of body development and of a possible correlation between the rate of weight and height gain and the onset of detectable sex hormone levels. Jugular blood was collected twice a week and stored at -20 degrees C until assay of progesterone by a solid phase RIA with a sensitivity of 0.32 nmol/L and of estradiol by liquid phase RIA adapted to low levels (3.67 pmol/L). the fillies were born with high serum levels of both hormones,which fell to undetectable levels by the first week of life. A variation in growth rate was observed, with the highest levels occuring from birth to the 3rd month of life, followed by a reduction until 15 mo of life, when fast growth was resumed. the monthly weight gain was 1.5% when the fillies reached puberty and 5.4% during the next month, (P<0.05, Friedman test). During this second period of accelerated growth after the beginning of progesterone production at detectable levels (above 0.318 nmol/L), the parameters of skeletal growth did not differ (P>0.05). the month of onset of puberty was the month of lowest weight gain in the life of the fillies, and it coincided with the highest insolation period. in conclusion, horses, like all other developed vertebrates, have a double pattern of development, with the acceleration observed at puberty depending on sex steroids, which in turn coincides with the highest insolation period. Gonadal activity characterized by serum progesterone levels was low from birth to the onset of puberty. After puberty the progesterone cycles were similar to those of adult animals with a mature hypothalamic-gonadal axis. (C) 1997 by Elsevier Science Inc.
- ItemSomente MetadadadosThe role of progesterone in memory: An overview of three decades(Elsevier B.V., 2015-02-01) Barros, L. A. [UNIFESP]; Tufik, S. [UNIFESP]; Andersen, M. L. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Memory comprises acquisition, consolidation and retrieval of information. Many substances can influence these different phases. It is well demonstrated that sex hormones, mainly estrogen, impact cognitive function. More recently, progesterone has also been documented as playing an important role in cognition, since it influences brain regions involved in memory. Currently, many women are under hormone treatment, which contain progesterone to decrease the risk of development of endometrial cancer. This affords the opportunity to study the real effects of this hormonal replacement on cognition. There are many contradictory results regarding the role of progesterone in memory. Therefore, the aim of this review was to synthesize these studies using the new perspective of the influence of hormone replacement on cognition in women. (C) 2014 Elsevier B.V. All rights reserved.