Concentration decrease of nitric oxide in the postischemic muscle is not only caused by the generation of O2-

Reperfusion of ischemic skeletal muscle is associated with an alteration of the concentrations of O(2) (-) and NO. In this study, the influence of epigallocatechin-3-gallate (EGCG), a known radical scavenger, on the balance of O(2) (-) and NO has been measured online in the skeletal muscle of Wistar rats. The hind limb of 14 male rats had been exposed to ischemic stress for 2 h. Seven rats received an infusion of 1.5 micromol EGCG/kg 5 min before reperfusion. O(2) (-), NO, and temperature were measured during reperfusion. The concentration of O(2) (-) declined under the influence of EGCG from 156.5 to 72.2 nmol/l (P = 0.01). The level of NO was found to decrease; this decrease was not significantly changed by EGCG (-175 nmol/l vs. - 227 nmol/l; P = 0.33). Thus the different superoxide concentrations did not correspond to different levels of NO, and the interaction of both radicals is not the only reason for the concentration decrease of NO in the reperfusion period. We conclude that EGCG protects skeletal muscle from I/R-injury without influencing the NO concentration profile to a large extent.