SUPPRESSION OF PROSTANOID FORMATION AND REGULATION OF PERIPHERAL-CIRCULATION AFTER SURGERY USING THROMBIN INHIBITOR (MD805)

We studied the effects of thrombin generation due to surgical stress o n prostanoid formation and peripheral circulation in anesthetized dogs . Three experimental groups were used, consisting of a control group ( group 1), a thoracotomized group (group 2), and a thoracotomized group treated with thrombin inhibitor (MD805: a synthetic arginine derivati ve) (group 3), The plasma concentrations of thrombin-antithrombin III complex (TAT) and prostanoids were measured along with the hemodynamic parameters. The plasma concentrations of TAT and thromboxane B-2 sigm ificantly increased 1 h after a thoracotomy in group 2. However, neith er concentration increased after a thoracotomy in group 3. The flow ra tio of the brachial and femoral arteries to cardiac output significant ly decreased 1 h after a thoracotomy in group 2, The's study indicates that thromboxane A(2) was thus synthesized by the stimulation of endo genous thrombin, while it also reduced the peripheral blood flow after surgery.