Differential modulation of [3H]flunitrazepam binding in female rat brain by sex steroid hormones.
Quantitative autoradiographic analysis revealed changes in [3H]flunitrazepam (a benzodiazepine agonist) binding in the anterior hypothalamus nucleus, the medial preoptic area and the cortico-medial amygdala nucleus following in vivo estradiol. The administration of 4 mg of progesterone, but not 1 mg, increased the binding of [3H]flunitrazepam in the basolateral amygdaloid nucleus and in the oriens-pyramidalis CA1 layer of the hippocampus. Exposure of brain sections in vitro to the potent, naturally occurring progesterone metabolite, 3 alpha-hydroxy-5 alpha-dihydroprogesterone, induced GABA-dependent changes in flunitrazepam binding, similar to the changes induced by progesterone, thus suggesting that different steroid mechanisms are implicated in the control of flunitrazepam binding.
Canonaco
M
M
Zoology Laboratory, University of Calabria, Italy.
Valenti
A
A
Tavolaro
R
R
Bettini
E
E
Maggi
A
A
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005445:Flunitrazepam / Q000378:metabolism*; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D012739:Gonadal Steroid Hormones; D011374:Progesterone; D004958:Estradiol; D005445:Flunitrazepam