Prostaglandin endoperoxides and thromboxane A2 in thrombus formation in the hamster cheek pouch in vivo.

Electrical stimulation in the presence of ADP of arterioles of the hamster cheek pouch caused endothelial damage and white thrombus formation. The thrombus formation was inhibited by cyclo-oxygenase inhibitors aspirin and sulphinpyrazone and its thioether derivative G 25671. Thromboxane synthetase inhibitors N-(7-carboxyheptyl) imidazole and butylimidazole failed to inhibit thrombus formation, although in the same doses both compounds inhibited serum levels of thromboxane. These results indicate that thromboxane is not important in thrombus formation in the hamster, but that prostaglandin endoperoxides are more significant. However, it is possible that the inhibition of white thrombus formation by aspirin, sulphinpyrazone and G 25671 may be mediated by a different mechanism altogether.