The effect of free radical scavengers on "in vivo" induced arterial thrombosis in relation to the arachidonate cascade.
Arterial platelet thrombosis induced by topical superfusion with adenosine diphosphate (ADP) is enhanced by tranylcypromine, an inhibitor of prostacyclin-synthetase. This effect is evanescent; indeed continuous superfusion with tranylcypromine results in a decrease of the thrombotic parameter to normal control values within forty minutes. This tachyphylactic-like phenomenon is attributed to the deactivation of cyclooxygenase by free radicals, probably oxygen species generated during the arachidonate cascade. In the presence of free radical scavengers such as uric acid, mannitol or formate the tachyphylactic phenomenon disappears suggesting that cyclooxygenase is no longer deactivated. The regression over time induced by tranylcypromine is computed as a measure for the inactivation of cyclooxygenase.
D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D016861:Cyclooxygenase Inhibitors; D005609:Free Radicals; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013927:Thrombosis / Q000139:chemically induced / Q000378:metabolism* / Q000517:prevention & control; D014191:Tranylcypromine / Q000494:pharmacology; D014527:Uric Acid / Q000494:pharmacology
D001095:Arachidonic Acids; D016861:Cyclooxygenase Inhibitors; D005609:Free Radicals; D014527:Uric Acid; D016718:Arachidonic Acid; D014191:Tranylcypromine