title: Activity of neurons in the preoptic area and their participation in reproductive senescence: Preliminary findings.
abstract: Alterations in the hypothalamic-pituitary-gonadal axis in females determine the transition from regular to irregular reproductive cycles, with loss of fertility. Stimulation of noradrenergic neurons of the anteroventral periventricular neurons (AVPV) is essential for regular reproductive cycles. Therefore, we examined the activity of neurons of the AVPV and measure the noradrenaline (NE) of acyclic rats, in constant estrus, and compared it with that of cyclic rats in estrus. Female cyclic (4-5 months) and acyclic (17-18 months) rats were euthanized at 10, 14, and 18 h in estrus. Brains were processed for immunoreactivity to antigens related to Fos (FRA) in AVPV, and the NE was determined by HPLC-ED. Plasma concentrations of LH, FSH, E2 and P4 were determined. In the acyclic animals, plasma LH was higher but the FSH was lower. There was decreasing P4 at different times, while the E2 was constant and lower in acyclic rats. FRA-ir expression in AVPV neurons of acyclic rats as well as turnover of NE was higher when compared with cyclic group. The preliminary findings showed increased activity in AVPV neurons in aging contribute to changes in the temporal pattern of neuroendocrine signaling, compromising the accuracy of inhibitory and stimulatory effects, causing irregularity in the estrous cycle and determining reproductive senescence.
authors.affiliation: Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, SBFis/UNESP, Univ Estadual Paulista, Araçatuba, São Paulo, Brazil; Laboratory of Endocrine Physiology and Aging, Department of Basic Sciences, Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: Larissa Brazolotto
authors.initials: LB
authors.lastname: Ferreira
authors.affiliation: Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, SBFis/UNESP, Univ Estadual Paulista, Araçatuba, São Paulo, Brazil; Laboratory of Endocrine Physiology and Aging, Department of Basic Sciences, Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: Angela Cristina
authors.initials: AC
authors.lastname: de Nicola
authors.affiliation: Laboratory of Neuroendocrinology, School of Dentistry of Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Janete Aparecida
authors.initials: JA
authors.lastname: Anselmo-Franci
authors.affiliation: Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, SBFis/UNESP, Univ Estadual Paulista, Araçatuba, São Paulo, Brazil; Laboratory of Endocrine Physiology and Aging, Department of Basic Sciences, Araçatuba Dental School, UNESP - Univ Estadual Paulista, Araçatuba, São Paulo, Brazil. Electronic address: rcdfisio@foa.unesp.br.
authors.forename: Rita Cássia Menegati
authors.initials: RC
authors.lastname: Dornelles
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D007031:Hypothalamus / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000097:blood; D009474:Neurons / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D011301:Preoptic Area / Q000378:metabolism*; D011374:Progesterone / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D012098:Reproduction / Q000502:physiology*
chemical_list: D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D009638:Norepinephrine
keywords: Acyclicity; Aging; Noradrenaline; Reproductive senescence