Noradrenergic mediation of the positive reinforcing properties of ethanol: II. Extinction of ethanol-drinking behavior in laboratory rats by inhibition of dopamine-beta-hydroxylase. Implications for treatment procedures in human alcoholics.

Following stabilization of consumption of a 15% (v/v) ethanol solution in a free-choice with water, rats were presented with a forced-choice of ethanol for 10 consecutive alternate days. Prior to each forced-choice presentation experimental animals were injected with the non-toxic dopamine-beta-hydroxylase inhibitor FLA-57 (30 mg/kg i.p.) while control animals received only vehicle injections. At the termination of the injection phase when ethanol was again made available in a free-choice with water, ethanol consumption for the FLA-57 treated animals was markedly suppressed. These data are interpreted in terms of extinction resulting from the procedure whereby performance of the ethanol drinking response was perpetuated by force with the pharmacological reinforcing properties being blocked by FLA-57-induced depletions of norepinephrine. Applications of these procedures in the treatment of human alcoholics are discussed.