Electrophoresis of platelet monoamine oxidase in schizophrenia and manic‐depressive illness

Abstract

Monoamine oxidase is an important enzyme in the catabolism of biogenic amines and can be measured in human platelets. Platelet MAO has been reported to be reduced in schizophrenic and manic-depressive patients, though other reports are contradictory. The present study evaluated the possibility that qualitative genetic enzyme abnormalities of MAO could be responsible for the different enzyme activities of platelet MAO in different populations. However, polyacrylamide gel electrophoresis of platelet MAO from 10 manic-depressive, 12 schizophrenic, and 11 normal individuals did not reveal any genetic mutant forms.

Metabolic Factors Affecting Monoamine Oxidase Activity

“…For example, reduced mitochondrial MAO activity has been observed in Downs' syndrome (Benson and Southgate 1971), essential hypertension (Sandier, Youdim, and Southgate 1970), migraine (Benson and Southgate 1971), toxemia of pregnancy (Sandier and Coveney 1962), celiac disease (Challacombe, Sandier, and Southgate 1971), juvenile diabetes mellitus (Wolf, Moshaim, and Bieber 1977), thyrotoxicosis (Levine et al 1962), alcoholism (Sullivan et al 1978b), chronic marijuana use (Stillman, Wyatt, and Murphy 1978), chronic schizophrenia (Wyatt, Potkin, and Murphy 1979) and bipolar affective disorder (Murphy and Weiss 1972). Elevated mitochondrial MAO activity has also been reported in a number of disorders, including unipolar depression (Nies et al 1971depression (Nies et al , 1974, bipolar affective disorder (Belmaker et al 1976), schizophrenia-related depressive disorders (Schildkraut, Orsulak, and Schatzberg 1978), dys-lexia, and glaucoma (E.A. Zeller, personal communication).…”

“…To evaluate hormonal influence on platelet MAO activity, Belmaker et al (1974) sampled blood for platelet MAO, plasma estradiol, and progesterone. Peak platelet MAO activity occurred around the ovulatory period, and lowest values occurred 5 to 11 days later.…”