Effects of progesterone on [35S] t-butylbicyclophosphorothionate binding in some forebrain areas of the female rat and its correlation to aggressive behavior.
The antiaggressive effects of progesterone (P) were evaluated in association with alterations in [35S] t-butylbicyclophosphorothionate (TBPS; chloride ion channel antagonist) binding in some forebrain sites of the female rat using in vitro quantitative autoradiography. The administration of 4 mg P was followed by a reduction in the frequency of different aggressive behaviors such as circling, nose-to-nose and fighting (mostly of the defensive nature) in ovariectomized (OVX) sexually mature rats, housed in pairs, during male-female encounters. Quantitative autoradiography data revealed that the same P dose, at the forebrain level, was responsible for low [35S] t-butylbicyclophosphorothionate binding levels in the medial preoptic area, lateral and basolateral amygdala nucleus and oriens-pyramidalis hippocampus CA1 layer, with even lower values being obtained following the in vitro addition of the potent P metabolite 5 alpha-pregnan-3 alpha-ol-20-one. These results suggests that the probable antiaggressive role of P during heterosexual encounters may be regulated by a local potent metabolite acting at the membrane site of the GABA complex.
Canonaco
M
M
Zoology Laboratory, University of Calabria, Italy.
Valenti
A
A
Maggi
A
A
D000374:Aggression / Q000187:drug effects*; D000679:Amygdala / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism*; D001643:Bridged Bicyclo Compounds / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic; D013196:Dihydrotestosterone / Q000378:metabolism; D005260:Female; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D005680:gamma-Aminobutyric Acid / Q000502:physiology
D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D013196:Dihydrotestosterone; D011374:Progesterone; D005680:gamma-Aminobutyric Acid; C037476:tert-butylbicyclophosphorothionate