Effect of progesterone on serotonin turnover in rats primed with estrogen implants into the ventromedial hypothalamus.
The effect of progesterone (P) on serotonin (5-HT) turnover was studied in nine brain regions in ovariectomized rats primed with bilateral intracerebral implants of estradiol benzoate (1:250 cholesterol) directed towards the ventromedial hypothalamus (VMN). Two days after surgery, animals received P (0.5 mg SC), and were pretested for lordosis behavior. After a 44-h recovery period, rats with LQ > or = 60 were randomly divided into groups that received either a second behavior test or IP injections of saline or pargyline (4 h after P or V). P treatment decreased pargyline-induced accumulation of 5-HT in the VMN (pars lateralis), the lateral midbrain central grey (IMCG), and the periventricular region (PVE, anterior hypothalamic region). The 5-HIAA/5-HT ratios were significantly decreased in the VMN and PVE in P-treated animals. These results support the hypothesis that P-influenced decreases in serotonergic activity in the VMN contribute to the facilitation of female receptivity, and also suggest that steroid-mediated actions in the VMN may lead to changes in serotonergic activity in the IMCG and PVE.
Gereau
R W
RW
Department of Biomedical Sciences, Southwest Missouri State University, Springfield 65804.
Kedzie
K A
KA
Renner
K J
KJ
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism; D004343:Drug Implants; D004837:Epinephrine / Q000378:metabolism; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D009928:Organ Specificity; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism*; D012726:Sexual Behavior, Animal / Q000187:drug effects*; D014697:Ventromedial Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism*
D001679:Biogenic Amines; D004343:Drug Implants; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D011374:Progesterone; D004958:Estradiol; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine