[Increased lipid peroxides generation and calcium fluxes in hearts during reperfusion]

To investigate the evidence for free radical generation and calcium influx as reperfusion injury, we studied the time course of lipid peroxides generation and calcium content in hearts during reperfusion. The study was performed in patients who had valve or coronary disease, and underwent open heart surgery. Lipid peroxides activity in plasma during reperfusion showed a significant (p less than 0.01) rise to a peak on 5 minutes of reperfusion (1.45 +/- 0.07 nmol/ml; mean +/- sem) compared to the level before reperfusion (1.37 +/- 0.07 nmol/ml) (n = 20). The lipid peroxides generation well correlated with aortic cross-clamp time (r = 0.6384, p less than 0.01). On the other hand, the atrial calcium content after 5-10 minutes of reperfusion was 118.5 +/- 14.9% of the level before cardiopulmonary bypass (n = 15), calcium/magnesium was 124.5 +/- 8.9% (p less than 0.05). That increase ratio well correlated with aortic crossclamp time (r = 0.5948, p less than 0.05). These results have produced evidence of increased oxidant activity and calcium influx in hearts during reperfusion. These results suggested that abnormal lipid peroxidation happened during reperfusion, and these peroxidation of the cell membrane might cause the membrane damage and then calcium influx.