The relation between protein carboxyl methylating and demethylating enzyme activities and noradrenaline efflux in platelets.

To test the hypothesis that the raised noradrenaline efflux rate constant in platelets observed in hypertensive individuals and some normotensive relatives to hypertensives could be ascribed to disturbances in the protein carboxyl methylation, protein carboxyl methylase activity and noradrenaline efflux rate constant were measured in platelets from 33 young healthy males. Sixteen had inheritance of hypertension. Protein methyl esterase activity and the noradrenaline efflux rate constant were measured in 43 men, 22 of whom had inheritance of hypertension. No correlation was found between unstimulated noradrenaline efflux from platelets and enzyme activity.