Enhancement of Endogenous Prostaglandin I2 (Prostacyclin) Generation In Vivo by a Phenolic Anti-Inflammatory Agent in the Rabbit

Abstract
Angiotensin II (i.v.) increased the plasma level of 6-keto-PGF1 alpha from 241 +/- 60 pg/ml (n = 8) to 612 +/- 108 pg/ml (n = 8) in anesthetized rabbits, which was further significantly increased by pretreatment with a phenolic anti-inflammatory agent, MK-447, to 1007 +/- 218 pg/ml (n = 8). MK-447 alone did not affect the level. The level of thromboxane B2 was not affected by these treatments. These results suggest that MK-447 may selectively enhance the PGI2 level by acting as a tryptophan-like cofactor of PG endoperoxide synthase.