Repeated cocaine administration reduces 5-HT1A-mediated prolactin secretion in rats.
The prolactin and behavioral responses elicited by the 5-HT1A agonist 8-OH-DPAT (8-hydroxy-2-[di-n-propylamino]tetralin) were examined in male rats previously exposed to chronic cocaine (15 mg/kg, i.p., b.i.d., 7 days) or saline. After 42 h of withdrawal, cocaine-treated rats exhibited a reduced prolactin response to 8-OH-DPAT challenge (50 micrograms/kg, i.v.). A 5-fold higher dose of 8-OH-DPAT stimulated maximal prolactin secretion that was similar in cocaine- and saline-treated rats. Prior cocaine treatment had no effect on the 5-HT syndrome induced by 8-OH-DPAT. Our data agree with the findings of others and suggest that 5-HT1A receptors mediating neuroendocrine secretion become subsensitive after repeated cocaine administration.
Baumann
M H
MH
Clinical Psychopharmacology Section, NIDA Addiction Research Center, National Institutes of Health, Baltimore, MD 21224, USA.
Rothman
R B
RB
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D003042:Cocaine / Q000494:pharmacology*; D007275:Injections, Intravenous; D008297:Male; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000494:pharmacology*; D012965:Sodium Chloride / Q000494:pharmacology; D013997:Time Factors
D012701:Serotonin; D012965:Sodium Chloride; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D011388:Prolactin; D003042:Cocaine