Objective: The present study was designed to investigate the cardioprotective effect of exogenous administration of bradykinin (BK) in cardiac surgery.
Methods: Forty-one patients who were scheduled for isolated coronary artery bypass grafting (CABG) were randomized into Control group and BK group. BK patients received 25 microg bradykinin infusion for 7 minutes before the cardiopulmonary bypass (CPB). Release of cardiac specific troponin I (TnI) and creatine kinase cardiac isoenzyme (CK-MB) was recorded. Perioperative circulating cytokine interleukin (IL)-6, 8 and 10 were measured.
Results: There was no significant difference in TnI between groups. However, BK patients released significantly less CK-MB than the controls (p =0.043). Systemic plasma levels of IL-6, IL-8 and IL-10 increased significantly after reperfusion in both groups as compared with baseline (p <0.05). The ratio of IL-8 to IL-10 was significantly lower in BK groups than in controls (p =0.03).
Conclusions: We conclude that exogenous administration of BK prior to CPB in CABG patients attenuates ischemic myocardial injury. It also shifts the circulating inflammatory cytokine balance towards the anti-inflammatory direction.