INTRACORONARY INFUSION OF REDUCED GLUTATHIONE IMPROVES ENDOTHELIAL VASOMOTOR RESPONSE TO ACETYLCHOLINE IN HUMAN CORONARY CIRCULATION

Background-Oxygen free radicals have been shown to cause endothelial v asomotor dysfunction, This study examined the effect of reduced glutat hione (GSH), an antioxidant, on human coronary circulation, Methods an d Results-Responses of epicardial diameter and blood flow of the left anterior descending coronary artery to intracoronary infusion of acety lcholine (ACh, 50 mu g/min) were measured by quantitative coronary ang iography and Doppler flow-wire technique, respectively, before and dur ing combined intracoronary infusion of GSH (50 mg/min) or saline in 26 subjects with no significant coronary stenosis. GSH infusion suppress ed the constrictor response of epicardial diameter to ACh and enhanced the increase in blood flow response to ACh, Furthermore, GSH potentia ted the coronary dilator effect of nitroglycerin. A beneficial effect of GSH on the epicardial diameter response to ACh was observed in a su bgroup of subjects with greater than or equal to 1 coronary risk facto rs but not in a subgroup without risk factors. Saline infusion did not have any effects. Conclusions-The results indicate that GSH improved coronary endothelial vasomotor function, particularly in subjects with coronary risk factors, and it potentiated the vasodilator effect of n itroglycerin in human coronary arteries.