Changes of antioxidant enzyme activities during cardiopulmonary bypass

Background. Reperfusion of ischemic heart causes the generation of free rad icals, and these radicals play an important role in post-ischemic tissue da mage. These free radicals are removed by scavenger enzymes and antioxidants in the cell. in this study, erythrocyte catalase, glutathione peroxidase a nd glutathione reductase enzyme activities were determined in patients unde rgoing cardiopulmonary bypass. Methods. Experimental design: Blood samples were obtained from the coronary sinus of patients at the following times: 1) Before cardiopulmonary bypass , 2) Immediately after cardiopulmonary bypass, 3) Fifteen minutes after the second specimen, 4) Thirty minutes after the second specimen. Patients: th is study was carried out on eleven patients undergoing open heart operation . Measures: catalase, glutathione peroxidase and glutathione reductase enzy me activities mere determined in these patients. Results. Catalase activity was significantly decreased in the third and fou rth groups as compared with the first group, which was also the control gro up (p < 0.05). Glutathione reductase activity in the third group was signif icantly higher as compared with control group (p < 0.001). However, there w ere no differences in glutathione peroxidase activity among control group a nd other three groups (p > 0.05). Conclusions. Our results indicate that the activities of antioxidant enzyme activities in erythrocytes are changed during the ischemia and reperfusion of the heart.