title: Estrogen Increases c-Fos expression in the paraventricular nucleus along with its anorexic effect in developing rats.
abstract: Estrogen inhibits food intake in cycling females in a variety of species. To determine how the development of the anorexic system by estrogen is regulated, rat pups at four developmental stages, postnatal day 11 (P11)-13, P20-22, P25-27 and P29-31, and adult ovariectomized (OVX) rats received a daily subcutaneous injection of 20 µg/kg of estradiol benzoate (EB) or vehicle for three days. Food intake, body weight gain and immunohistochemical c-Fos expression in the brain were measured after each injection. EB treatment decreased both food intake and body weight gain from P27 onwards and significantly increased c-Fos expression in the parvocellular division of the paraventricular nucleus of the hypothalamus (pPVN), which is coincident with its anorexic effect in developing rats. The pattern of EB-induced c-Fos activation in other feeding-related nuclei did not coincide with its anorexic effect in developing pups. However, in adult OVX rats, EB treatment increased c-Fos expression in the nucleus tractus solitarius (NTS), the central nucleus of the amygdala (CeA), and, to a lesser degree, the ventromedial nucleus of the hypothalamus (VMH). These results suggested that the pPVN is an essential site in the brain for controlling the anorexic effect of estrogen and that the feeding system of rat begins to respond to estrogen before the onset of puberty (P25-28).
authors.affiliation: Department of Integrative Physiology, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
authors.forename: Jing Hua
authors.initials: JH
authors.lastname: Chi
authors.forename: Kazumi
authors.initials: K
authors.lastname: Narita
authors.forename: Toru
authors.initials: T
authors.lastname: Ichimaru
authors.forename: Takuya
authors.initials: T
authors.lastname: Murata
mesh_terms: D000679:Amygdala / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000855:Anorexia / Q000139:chemically induced* / Q000378:metabolism; D004435:Eating / Q000187:drug effects; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D008297:Male; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects* / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D051381:Rats; D017208:Rats, Wistar; D017552:Solitary Nucleus / Q000187:drug effects / Q000378:metabolism; D014697:Ventromedial Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism; D015430:Weight Gain / Q000187:drug effects
chemical_list: D004967:Estrogens; D016760:Proto-Oncogene Proteins c-fos