Central and peripheral components of the inhibitory actions of 5-HTP on ethanol consumption in the rat.
When administered under a backward conditioning paradigm, 5-HTP administration resulted in a decrease in ethanol intake followed by a persistently decreased ethanol consumption. A central component to this inhibitory effect was suggested by the inability of xylamidine to significantly reduce the initial inhibitory effect of 5-HTP. The persistent rejection was prevented by xylamidine. Methysergide reduced the initial as well as the persistent effects of 5-HTP. In studies utilizing a forward conditioning paradigm, 5-HTP and lithium were each effective in developing CTAs to ethanol and saccharin. Only the ethanol-5-HTP pairing showed a persistent aversion. A peripheral component to the actions of 5-HTP was suggested by xylamidine blocking the CTAs induced by 5-HTP. Xylamidine also prevented the persistent ethanol avoidance induced by 5-HTP, but was ineffective in antagonizing lithium-induced CTAs. These results suggest central as well as peripheral components associated with the inhibitory effects of 5-HTP on ethanol consumption. Central actions appear to mediate the initial inhibitory effects while peripheral actions appear to be associated with persistent avoidance of ethanol following 5-HTP treatment.
Zabik
J E
JE
Department of Pharmacology and Toxicology, School of Pharmacy and Pharmacal Sciences, Purdue University, West Lafayette, IN 47907-1334.
Sprague
J E
JE
Binkerd
K
K
D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000428:Alcohol Drinking / Q000523:psychology*; D000578:Amidines / Q000494:pharmacology; D000818:Animals; D002490:Central Nervous System / Q000187:drug effects*; D003216:Conditioning, Operant / Q000187:drug effects; D003864:Depression, Chemical; D008094:Lithium / Q000494:pharmacology; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D017933:Peripheral Nervous System / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012439:Saccharin / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism; D012702:Serotonin Antagonists / Q000494:pharmacology; D013649:Taste / Q000187:drug effects
D000578:Amidines; D012702:Serotonin Antagonists; D012701:Serotonin; D008094:Lithium; D006916:5-Hydroxytryptophan; D012439:Saccharin; C005894:xylamidine; D008784:Methysergide