Inhibition of thromboxane A2 production by trapidil and trapidil derivatives in the arachidonic acid-injected rat

Abstract

Trapidil and four selected 5,7-disubstituted s-triazolo (1,5-a)pyrimidine derivatives (AR 12456, AR 12463, AR 12464, AR 12465) which have already been shown to possess inhibitory effects on arachidonic acid(AA)-induced aggregation and thromboxane A₂(TXA₂) formation in human and rabbit platelets in vitro diminished the AA-stimulated TXAZ production in murine blood in vivo. The inhibitory effects of the derivatives were generally stronger than those of trapidil. The strongest inhibitor of TXA₂ formation was the derivative AR 12456. These in vivo results correspond well with our previous in vitro findings.