title: Estrogen reduces cholecystokinin-induced c-Fos expression in the rat brain.
abstract: Recent reports have shown that estradiol increases the hypophagic effect of exogenous cholecystokinin-octapeptide (CCK). CCK is known to increase the expression of Fos, a marker of neuronal activation, in specific medullary and hypothalamic nuclei. The present experiment tested the hypothesis that as estradiol enhances that behavioral effects of CCK, there is a parallel amplification of CCK-induced Fos expression. Instead, estradiol pretreatment reduced the level of CCK-induced Fos expression in the nucleus of the solitary tract (NTS) and in the medial parvocellular region of the hypothalamic paraventricular nucleus (PVN). The number of Fos-containing cells in the supraoptic nucleus and other regions of the PVN were not affected by estradiol pretreatment. The results are consistent with the hypothesis that the NTS and/or the PVN may mediate the estrogen-induced increased sensitivity to peripheral inhibitory signals in the control of food intake.
authors.affiliation: Department of Psychology, University of Pennsylvania, Philadelphia 19104-6196, USA.
authors.forename: L M
authors.initials: LM
authors.lastname: Flanagan-Cato
authors.forename: J F
authors.initials: JF
authors.lastname: King
authors.forename: J G
authors.initials: JG
authors.lastname: Blechman
authors.forename: M P
authors.initials: MP
authors.lastname: O'Brien
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002766:Cholecystokinin / Q000494:pharmacology*; D004435:Eating / Q000187:drug effects; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D016762:Genes, fos / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004958:Estradiol; D002766:Cholecystokinin