PLATELET ADENYLYL-CYCLASE ACTIVITY IN ALCOHOLICS AND SUBTYPES OF ALCOHOLICS

Adenylyl cyclase (AC) activity was measured in membrane preparations o f platelets from control and alcoholic subjects. The sample consisted of 51 alcoholics who were categorized as type I or type II using the c riteria of Gilligan et al. (Genet. Epidemiol. 4:395-414, 1987) and 54 normal controls. Alcoholic males exhibited significantly lower values than controls in basal and fluoride-stimulated platelet AC activity. W hen male alcoholics were segregated into type I and type II categories , the platelet AC activity did not differ between subtypes, and both s ubtypes had AC activity that was below control values. Western blot an alysis of the quantity of G(s) alpha and G(i) alpha proteins in a subs et of male controls and alcoholic subjects demonstrated no significant relationship between quantity of G proteins and AC activity. The resu lts confirm lower platelet AC activity in male alcoholics, compared wi th controls. Given the lack of quantitative relations between G(s) alp ha and G(i) alpha proteins and AC activity, the results support the co ntention that individual differences in platelet AC activity in the al coholic subjects may reflect quantitative or qualitative differences i n the AC catalytic units.