THYROTROPIN-RELEASING-HORMONE ANALOG TA-0910 SUPPRESSES ALCOHOL INTAKE IN ALCOHOL-DRINKING AFRICAN-GREEN MONKEYS

In previous studies, we found that single injections of the thyrotropi n-releasing hormone analog TA-0910 dose-dependently reduced alcohol in take and preference in alcohol-preferring (P) and Fawn-Hooded (FH) rat s over a 24-hr period of continuous access to alcohol and water, Howev er, several consecutive daily injections of TA-0910 resulted in the de velopment of tolerance to these effects, In the present study, we foun d that in a 5-hr limited-access schedule in which monkeys could select an aqueous alcohol solution (7.5% v/v) or tap water, single doses of TA-0910 (0.0625, 0.125, 0.25, 0.5, and 0.75 mg/kg), similar to those f ound effective in P and FH rats, reduced consumption of alcohol. In th is protocol, tolerance to the attenuating effects of TA-0910 on alcoho l intake was not evident after five consecutive once-daily doses of 0. 5 mg/kg. Furthermore, it was shown that a single dose of 0.75 mg/kg TA -0910 did not significantly influence 24-hr water intake when water wa s the only available fluid, but did reduce the intake of a preferred s olution of saccharin, These findings suggest that activation of brain thyrotropin-releasing hormone systems reduces alcohol intake in primat es and that tolerance to this effect is not evident within 5 days unde r a limited access schedule.