Phospholipase A2 in experimental hypertension

An assay method has been developed to measure phospholipase A2 (PLA2) in ratserum and to study the possible role of this enzyme in experimental hypertension. Experiments with rat serum following 48 h of bilateral nephrectomy indicated a decrease inPLA2 activity, suggesting that kidneys might be playing an important role in regulating serum PLA2 activity and that kidneys might be a source of this enzyme. Experiments with renal hypertensive rats, spontaneously hypertensive rats, and rats receiving a low-salt diet demonstrated that a decrease in PLA2 activity was found only in those conditions in which elevated plasma renin activity was accompanied by elevated blood pressure. When elevated plasma renin activity was not accompanied by elevated blood pressure, serum PLA2 activity was unchanged. These observations represent the first biochemical separation between conditions of elevated plasma renin activity without an increase in blood pressure and conditions of elevated plasma renin activity with an increasein blood pressure.