Serum phospholipase--regulatory and pathophysiological aspects.

The development of a photometric procedure to measure phospholipase A activity has extended previous observations that this enzyme activity increases in several pathological states including pancreatic and inflammatory diseases. Serum phospholipase A in pancreatitis was characterized as a mixture of the pancreatic enzyme and a different phospholipase with a pH optimum at 8.0. The latter enzyme was also observed in nonpancreatic diseases like septicemia and acute lung failure which are characterized by an increase in tissue phagocyte activity. The possible pathogenic role of phospholipase(s) A, their intracellular regulation and the proposed mechanisms of release into the blood stream are discussed with respect to the present pathobiochemical knowledge. This includes the mechanism of activation of phagocytosis and the possible role of lipocortins known to be stimulated by glucocorticoid treatment.