[Changes in urinary immunoreactive-TXB2 and 2,3-dinor TXB2 in man following cardiopulmonary bypass]

We measured urinary levels of i-TXB2, 2,3-dinor TXB2 and NAG following cardiopulmonary bypass (CPB) and studied their clinical significance. Subjects studied were 8 patients undergoing cardiac surgery. In the CABG group, urinary i-TXB2, 2,3-dinor TXB2 and NAG level increased significantly (P less than 0.05) 3hrs after CPB, but decreased on and after the 1st postoperative day. In the DVR group, these levels showed similar changes, but i-TXB2 and NAG levels were significantly (P less than 0.05) higher than those of the CABG on the 1st or 3rd postoperative day. A significant correlation (r = 0.84, P less than 0.05) was observed between NAG and i-TXB2 on and after 2nd postoperative day. The results suggest that urinary i-TXB2 during the period immediately after CPB is derived from platelets and reflects the functional changes in renal urinary tubules, while urinary i-TXB2 level on and after the 2nd postoperative day reflects the function of the renal urinary tubules.