Long-lasting suppression of alcohol preference in rats following serotonin receptor blockade by ritanserin.
Rats with developed preference for 3% ethanol were injected subcutaneously (SC) with 10 mg/kg of the 5HT2 antagonist ritanserin for 9 days. This resulted in a marked and significant suppression of alcohol preference, as compared to controls. The effect was very long-lasting, as shown by the fact that it was still evident up to 20 days after the end of the treatment. Since ritanserin shows some affinity also for D2-dopaminergic receptors (even though much lower than for 5HT2 receptors), for comparison, other rats were injected SC for 9 days with 0.0625 mg/kg of haloperidol or with its vehicle. The effect of haloperidol treatment was low and short-lasting. Depletion of endogenous serotonin by p-chlorophenylalanine (600 mg/kg x 3 days) completely abolished the suppression of alcohol preference by ritanserin. These results suggest that: 1) the ritanserin-induced reduction of alcohol preference is not due to dopaminergic blockade, 2) that the effect of ritanserin is completely dependent on the endogenous serotoninergic mechanisms.
Panocka
I
I
Department of Behavioral Physiology, Polish Academy of Sciences, Mrokow.
Massi
M
M
D000428:Alcohol Drinking; D000818:Animals; D003864:Depression, Chemical; D010134:Fenclonine / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D016713:Ritanserin / Q000494:pharmacology*; D012702:Serotonin Antagonists
D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D016713:Ritanserin; D006220:Haloperidol; D010134:Fenclonine