Role of eicosanoids in the kappa-carrageenin rat tail thrombosis.

Pretreatment of rats by the cyclooxygenase inhibitors diclofenac, phenylbutazone, and aminophenazone did not influence kappa-carrageenin (KC) rat tail thrombosis (RTT) whereas pretreatment by aspirin, at high doses, and particularly sulfinpyrazone decreased RTT frequency, PGI2 or iloprost i.v. injection showed strong RTT preventing effects as it was also seen by thromboxane synthesis inhibitors (benzydamine, imidazole) at high doses. The PAF antagonist BN 52020 weakly protected. Lipoxygenase inhibitors (quercetin, oxphaman a.o.) proved ineffective. Therefore, thromboxane/PGI2 balance and partly PAF seem to be involved in the mechanism of KC RTT.