[Changes in alcohol choice by chronically alcoholized cats as affected by tryptopham, its metabolites and...

In cats unrestrictedly selecting alcohol and water during 5 months - 4.5 years under normal feeding, intraperitoneal injection of 1-tryptophan (5.5 and 65 mg/kg) lowered alcohol intake. Depending on the effect on water intake, a decrease (after a lower dose) or an increase (after a higher dose) in alcohol preference was observed. Tryptophan metabolites (mg/kg): dl-5-hydroxytryptophan (5-HTP, 6 and 12), tryptamine (2.5 and 5), 1-4 and dl-(2 and 6)kynurenine, as well as drugs modifying tryptophan metabolism, such as Ro-4-4602(2), an inhibitor of peripheral decarboxylase of aromatic amino acids, and allopurinol (2), an inhibitor of tryptophan pyrrolase (10 and 17), enhanced alcohol intake. Preference of alcohol was increased after tryptamine and 1-kynurenine and decreased after 5-HTP administration. Control injections of saline and distilled water resulted in a significant increase in alcohol and water intake. Saline increased preference of alcohol.