Nature of the Inhibition of Thrombin Formation by Sulfhydryl-Oxidizing Agents

¹ From the Department of Surgery, Presbyterian Hospital, affiliated with the College of Medicine, University of Illinois, Chicago, Illinois

Thrombin formation has been shown to be inhibited by oxidized glutathione and other sulfhydryl-oxidizing agents. This effect is observed with purified bovine prothrombin and with prothrombin as present in human plasma. It is different in nature from a similar inhibition brought about by sulfhydryl-containing (reducing) substances. Experiments with purified clotting factors and a variety of plasma and serum preparations have been carried out in order to elucidate the nature of the inhibition produced by SH-oxidizing substances. The results obtained indicate that thrombin formation is inhibited by these reagents as a result of their reaction with Ac-globulin sulfhydryl groups leading to partial or complete inactivation of this accelerator.