Atividade dos neurônios do núcleo anterovental periventricular e sua participação no envelhecimento reprodutivo de ratas

• Ano de defesa: 2015
• Autor(a) principal: Ferreira, Larissa Brazolotto [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Envelhecimento; Norepinefrina; Gonadotropinas; Estrogênios; Aging
• Link de acesso: http://hdl.handle.net/11449/134195; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/28-01-2016/000857749.pdf

Changes of the hypothalamic-pituitary-gonadal axis in females determine the transition from regular to irregular reproductive cycles, with a loss of fertility. Interaction of GnRH neurons and gonadal steroid is connected by feedback and changes in this mechanism are related to reproductive senescence. Noradrenaline (NE) stimulation and preoptic area (POA) neurons are essential for release of gonadotropins, as GnRH neurons express receptors for estrogen β and progesterone. The objective of this study was to evaluate the activity of neurons in POA nuclei, in transition period for estropause in Wistar rats. Cyclic Wistar rats (4-5 months) on the day of estrus and acyclic (17-18 months) in estrus constant (CE) were decapitated or perfused at 10, 14 and 18 hours. Perfused brains were processed for immunohistochemistry to evaluate the immunoreactivity to antigens related to the Fos in POA. After decapitation, the brain was removed and carried microdissection of POA and determining the content of NE and its metabolite; Plasma was used for measurements of LH, FSH, E2 and P4. The results showed higher plasma secretion of LH, FSH and E2 lower in the group of acyclic rats. The number of FRA-IR neurons was higher in acyclic rats in the 10 hours (p <0.001) and 18 (p <0.05) compared to the group of animals with regular cycle. In rats acyclic, the stored contents of NE was lower at 14h and 18h (p <0.001), and the metabolite was constant and greater at 18h compared to the same time of the rats of the cyclic group (p <0.05). It follows that neural and ovarian changes that occur in the CE decline to determine the occurrence of cyclicity of cycles and featuring periestropausa period