['Cardiopulmonary bypass (CPB) is characterized by the systemic release of proinflammatory cytokines, such as tumor necrosis factor-alpha and the interleukins 1 and 6, as well as endogenous antiinflammatory cytokines, including interleukin-10 (IL-10). Glucocorticoids reduce tumor necrosis factor-alpha plasma concentrations while enhancing IL-10 plasma concentrations after CPB. Aprotinin, a serine protease inhibitor used primarily to reduce blood loss after CPB, reduces CPB-induced proinflammatory cytokine tumor necrosis factor-alpha release similarly to glucocorticoids. This study evaluates the effect of full-dose aprotinin on the plasma concentrations of IL-10 after CPB.', 'Twenty adults were randomized into a control (group C, n = 10) and a full-dose aprotinin-treated group (group A, n = 10). Plasma levels of IL-10 were measured by enzyme-linked immunosorbent assay technique at baseline (before anesthetic induction), and at 1 and 24 hours after CPB termination.', 'A significant (p < 0.05) increase of IL-10 occurred in both groups at 1 and 24 hours after termination of CPB when compared with the same group at baseline. In group A, the increase in IL-10 was significantly greater than in group C (p < 0.05) at 24 hours after CPB.'] Does aprotinin enhance the endogenous release of interleukin-10 after cardiac operations?