Dopamine-beta-hydroxylase activity and ethanol-induced sleep time in selectively bred and heterogeneous stock mice.

Dopamine-fS-hydroxylase (DBH), the enzyme responsible for the conversion of dopamine to norepinephrine, was measured in the plasma of two lines of mice selectively bred for differential sensitivity to hypnotic doses of ethanol. Plasma levels of DBH were measured by radioenzymatic assay in long sleep (LS) and short sleep (SS) male and female mice which had no prior exposure to ethanol. LS mice had ,significantly higher plasma DBH activity than did SS mice, although no significant sex difference was found. Fusaric acid, an inhibitor of both central and peripheral DBH, attenuated sleep time induced by either 3 or 4 g/kg ethanol in mice of a heterogeneous genetic stock. The results of these experiments may further implicate noradrenergic systems in mediating some of the depressed effects of ethanol.