Platelet and plasma amine oxidase activity in 680 normals: Sex and age differences and stability over time

Platelet and plasma amine oxidase activities in 680 normals exhibited unimodal frequency distributions and Females had 20% higher mean platelet amine oxidation activities, but there were no male-female differences in the plasma enzyme.

Abstract

Abstract Platelet and plasma amine oxidase activities in 680 normals exhibited unimodal frequency distributions. Females had 20% higher mean platelet amine oxidase activities, but there were no male-female differences in the plasma enzyme. Age was not significantly correlated with either platelet or plasma amine oxidase activities. The activities of the two enzymes were not significantly intercorrelated. Platelet amine oxidase activity measured with benzylamine as the substrate in a rapid assay based upon platelet counts was highly correlated (r = 0.88) with activity measured in platelet pellets with tryptamine as the substrate. Benzaldehyde and indoleacetaldehyde were identified as the principal products in these assays. Platelet and plasma amine oxidase activities determined three times in the same individuals yielded similar results after approximately 2-week (r = 0.94, 0.97) and 2-month (r = 0.86, 0.84) intervals.