PLATELET MONOAMINE-OXIDASE ACTIVITY IN ALCOHOLICS, ALCOHOLICS WITH DRUG-DEPENDENCE, AND COCAINE ADDICTS

The main objective of this investigation was to study the influence of drug dependence on platelet monoamine oxidase (MAO) activity in the p resence and absence of alcoholism. One hundred and thirteen admissions to alcohol and drug treatment facilities participated in the study. T wenty-six met the criteria for alcoholism (group I), seventy-eight sub jects were alcohol-/cocaine- and cannabis dependent (group II), and th e remaining nine were patients with DSM-III-R diagnosis of cocaine add iction (group III). MAO activity was assayed radiochemically with [C-1 4]tyramine as a substrate (221 mu M). The results of this study showed that platelet MAO activity [nmol of product formed x (mg protein)(-1) x hr(-1)] (mean +/- SE) was significantly (p < 0.01) lower in all of these subjects (group 1, 5.50 +/- 0.80; group II, 3.90 +/- 0.50; group III, 4.3 +/- 1.60) as compared with controls (14.85 +/- 1.13). Measur ements of platelet MAO activity may provide us with a reliable biochem ical marker for alcoholism and perhaps addiction to other substances o f abuse (i.e., cocaine).