EFFECT OF ISCHEMIA-REPERFUSION ON GLUTATHIONE-PEROXIDASE, GLUTATHIONE-REDUCTASE AND GLUTATHIONE TRANSFERASE ACTIVITIES IN HUMAN HEART PROTECTED BY HYPOTHERMIC CARDIOPLEGIA

The activities of glutathione peroxidase (GSH-px). glutathione reductase (GSSG-rx) and glutathione transferase (GST) were measured in myocardial specimens obtained from right atria of patients subjected to different period of ischaemic arrest (aortic clamping ranging from 10 min to 90min) followed by 60min. of reperfusion, during open heart surgery 41-90min. period of aortic clamping induced a significant increase of GSH-px activity with both H2O2 (p < 0.05) and cumene hydroperoxide (p < 0.025) as substrates when compared with baseline levels. Aortic clamping and reperfusion, however did not significantly change the myocardial activities of glutathione transferase and glutathione reductase. It is suggested that the increase of GSH-px in ischaemic-reperfused human hearts may render the myocardium less susceptible to oxidative attack particularly during the reoxygenation period when the level of active oxygen species is greatly elevated. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.