Thrombin and bradykinin modulate prostaglandin synthetase independently of phospholipase.

Thrombin and bardykinin stimulate prostaglandin production from exogenous arachidonic acid in 3T3 cells. The increase in PG production cannot be explained simply by the contribution from endogenous AA metabolism. The rates of stimulated PG production from exogenous and endogenous AA both remain linear fro 3 min, then fall rapidly. It is suggested that BK and Th may act by directly stimulating cyclooxygenase independently of phospholipase.