Phospholipase inhibition and the mechanism of angiotensin-induced prostacyclin release from rat mesenteric vasculature.

Abstract

Generation of prostaglandins by arterial vasculature of rats was measured by perfusing the isolated mesenteric arterial vascular bed with Krebs-Henseleit solution. The effluent directly superfused bioassay tissues in cascade, and aliquots were collected for subsequent chromatography and radioimmunoassay. Injection of arachidonate (1-10 μg) or angiotensin II (0.1-0.5 μg) through the mesentery caused release of a PGI2-like substance. After extraction and Chromatographic separation of the mesenteric effluent, it was confirmed by radioimmunoassay that 6-oxo-PGF1α (the hydration production of PGI2) is the predominant prostanoid generated from exogenous arachidonate. Release of 6-oxo PGF1α and PGE..