A re-evaluation of the role of tetrahydropapaveroline in ethanol consumption in rats.
The role of tetrahydropapaveroline (THP), a condensation product of a dopaldehyde with dopamine, in the regulation of alcohol consumption was investigated. In the first experiment, rats received intraventricular injections of either racemic THP hydrobromide (0.65 or 1.3 microg/microl), R-(+)-THP (0.66 or 1.4 microg/microl), or an equal volume of vehicle. The lower doses of both (+/-)-THP and (+)-THP significantly increased volitional alcohol intake. For the racemic compound, the increase was significant at 7-13% concentrations. The R-(+)-enantiomer increased consumption at 4-11 and 15-20% concentrations of ethanol. The higher doses of both compounds did not significantly alter alcohol preference. A second experiment evaluated the chronic effect of THP delivered subcutaneously via osmotic minipump. Animals receiving THP (0.1, 0.5, 1.0, 2.0, and 4.0 mg/ml) did not differ in their alcohol intake, compared to vehicle-treated controls. Whether or not endogenously formed THP participates in the etiology of alcohol addiction remains unclear. Nonetheless, there are few known compounds that induce a preference for unsweetened alcohol solutions over water in laboratory animals.
McCoy
John G
JG
Department of Psychology, University of Southern Mississippi, Hattiesburg, MS 39406, USA. John.McCoy@usm.edu
Strawbridge
Chris
C
McMurtrey
Kenneth D
KD
Kane
Victoria B
VB
Ward
Christopher P
CP
D000428:Alcohol Drinking / Q000503:physiopathology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000187:drug effects*; D004333:Drug Administration Routes / Q000662:veterinary; D005518:Food Preferences; D007276:Injections, Intraventricular / Q000379:methods; D008297:Male; D010208:Papaverine / Q000031:analogs & derivatives / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism; D013765:Tetrahydropapaveroline / Q000031:analogs & derivatives / Q000494:pharmacology*
D013765:Tetrahydropapaveroline; D010208:Papaverine