MDMA produces a conditioned place preference and elicits ejaculation in male rats: a modulatory role for the endogenous opioids.
Methylenedioxymethamphetamine (MDMA) can produce a conditioned place preference (CPP) among rats. The ability of MDMA to produce a CPP was assessed while some rats were under the influence of naltrexone, 56 mg/kg, given 4 h before conditioning. Naltrexone attenuated MDMA's ability to produce a CPP without completely blocking MDMA's effects. Having noticed previously the production of seminal plugs by rats receiving MDMA, the presence of seminal plugs was recorded across the 8 days of conditioning. Roughly half of the rats receiving 6.3 mg/kg of MDMA left plugs during the conditioning period, while over two-thirds of those receiving a combination of MDMA and naltrexone left plugs. A second study, assessing further doses of MDMA, tabulated the drug's effects on the production of seminal plugs across 3 h. Besides eliciting ejaculation, MDMA also led to increased urination and defecation and a loss of body weight. These results support suggestions that the endogenous opioids modulate the reinforcing properties of stimulant drugs and affect male sexuality.
Department of Psychology, Rensselaer Polytechnic Institute, Troy, NY 12180.
E J
EJ
Bilsky
C L
CL
Hubbell
J D
JD
Delconte
L D
LD
Reid
D015104:3,4-Methylenedioxyamphetamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D003216:Conditioning, Operant / Q000187:drug effects*; D003672:Defecation / Q000187:drug effects; D004542:Ejaculation / Q000187:drug effects*; D004723:Endorphins / Q000502:physiology*; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D009271:Naltrexone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012702:Serotonin Antagonists / Q000494:pharmacology; D014326:Tropanes / Q000494:pharmacology; D014554:Urination / Q000187:drug effects
D004723:Endorphins; D012702:Serotonin Antagonists; D014326:Tropanes; D015104:3,4-Methylenedioxyamphetamine; D009271:Naltrexone; D018817:N-Methyl-3,4-methylenedioxyamphetamine; C042253:bemesetron