Reversal of androgen inhibition of estrogen-activated sexual behavior by cholinergic agents.
Androgens have been found to inhibit lordosis activated by estrogen treatment of ovariectomized female rats. In the present experiments, dihydrotestosterone propionate (200 micrograms for 3 days) inhibited the incidence of lordosis in ovariectomized females treated with estradiol benzoate (1 microgram for 3 days). This inhibition of lordosis was reversed 15 min after bilateral intraventricular infusion of physostigmine (10 micrograms/cannula), an acetylcholinesterase inhibitor, or carbachol (0.5 microgram/cannula), a cholinergic receptor agonist. This reversal of inhibition appears to be mediated by cholinergic muscarinic receptors since pretreatment with scopolamine (4 mg/kg, ip), a muscarinic receptor blocker, prevented the reversal of androgen inhibition by physostigmine. These results indicate that androgens may inhibit estrogen-activated lordosis through interference with central cholinergic muscarinic mechanisms.
Dohanich
G P
GP
Department of Psychology and Neuroscience Program, Tulane University, New Orleans, Louisiana 70118.
Cada
D A
DA
D000818:Animals; D001921:Brain / Q000187:drug effects; D002217:Carbachol / Q000494:pharmacology; D013196:Dihydrotestosterone / Q000031:analogs & derivatives* / Q000494:pharmacology; D004357:Drug Synergism; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D010277:Parasympathomimetics / Q000494:pharmacology*; D010830:Physostigmine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011944:Receptors, Androgen / Q000187:drug effects*; D011950:Receptors, Cholinergic / Q000187:drug effects*; D011960:Receptors, Estrogen / Q000187:drug effects*; D012601:Scopolamine / Q000494:pharmacology; D012726:Sexual Behavior, Animal / Q000187:drug effects*
D010277:Parasympathomimetics; D011944:Receptors, Androgen; D011950:Receptors, Cholinergic; D011960:Receptors, Estrogen; D013196:Dihydrotestosterone; D004958:Estradiol; C030445:dihydrotestosterone propionate; D002217:Carbachol; D010830:Physostigmine; D012601:Scopolamine