Changes in antioxidant enzyme activities in erythrocytes in patients undergoing CABG – A pilot study

Background: Surgical myocardial revascularisation surgery (coronary artery bypass grafting CABG) with extracorporeal circulation (ECC) triggers systematic oxidative stress, which is responsible for a large number of postoperative complications. It has been suggested that reactive oxygen species (ROS) arise not only during surgery, but also in the reperfusion period. The aim of this study was to analyze some antioxidant enzyme activities in erythrocytes in patients undergoing CABG. Patients and Methods: 15 men aged between 50–72 who had undergone elective CABG with ECC were examined. None of them had received catecholamine infusion during the whole examination period. The superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities were measured at 5 time points: 1/ before anaesthesia, 2/ during the ECC, 3/ immediately after surgery, 4/ 18 hours after surgery, 5/ 42 hours after surgery. The spectrophotometric methods were used for erythrocyte SOD, GPx and CAT activity measurements. The results were statistically analyzed. p<0.05 was considered as significant. Results: The mean time of anaesthesia was 212 min ± 24, surgery – 185.22 min ± 22.17, ECC – 68.06 min. ± 14.02. GPx increased significantly only during ECC (2nd time point), SOD and GPx increased at 4th and 5th time points. Additionally, there were significant negative correlations between GPx activities and duration of ECC at 4th time point. Conclusions: 1/ ECC resulted in increase in GPx. 2/ CABG surgery leads to increase in SOD and CAT during the early postoperative period. 3/ Erythocyte GPx activity was related to the duration of ECC.