Protective effect of alpha-tocopherol and L-ascorbic acid against the ischemic-reperfusion injury in patients during...

The purpose of the investigation was: 1. to examine the effect of cardiopulmonary bypass (CPB) on the generation of cytotoxic oxygen-derived radicals and 2. to determine if the pretreatment of patients with vitamins E and C will combat generation of such radicals. Twenty patients undergoing CPB for treatment of cardiac disease were entered into the study and randomized to one of two groups. Group 1 (n = 9) served as control. Group 2 (n = 11) consisted of patients pretreated with 2000 IU of vitamin E 12 h prior to surgical intervention and 2 g of vitamin C given in the morning on the day of operation. Blood samples from arterial and mixed venous blood for analysis were obtained at the following intervals: 1. before anesthesia, 2. before sternotomy, 3. at the start of CPB, 4. at the end of CPB, 5. at the time of skin closure, 6. in the morning of the following day. Blood specimens from the coronary sinus were withdrawn A--before aortic cross-clamping, B--immediately after aortic declamping, C--in the 5th min, and D--in the 15th min of reperfusion. The concentration of inorganic phosphate as well as of uric acid was significantly higher in the control group what might indicate that vitamins E and C attenuate the degradation of adenine nucleotides. The most important difference between treated and control groups was observed in plasma concentration of malondialdehyde--a marker of lipid peroxidation--which was significantly lower in pretreated patients. A similar pattern of changes was found in the level of the lysosomal enzyme N-acetyl-glucosaminidase. Finally, pretreatment with vitamins E and C inhibited the decrease of catalase, observed in controls.