Serum phospholipase A2 and lysolecithin changes following myocardial infarction.

We have examined changes in the activities of phospholipase A2 (PLA2) and the concentrations of total choline-phospholipids and lysolecithin, in serum from patients following a myocardial infarction by comparison with patients suffering from unstable angina. A significant increase in PLA2 activity was found after myocardial infarction. The peak increase occurred approximately 36 h after infarction. No significant PLA2 change was found in the patients with unstable angina. Concentrations of lysolecithin, the major metabolite of PLA2 activity, were high in the admission samples from the infarction patients, followed by an overall fall during the first 24 h: the concentrations in the patients with angina were normal. PLA2 and lysolecithin changes post-infarction showed they were involved in processes not occurring in angina.