Glutamate accumulation and increased hydroxyl free radical formation in the abdominal aorta and heart of gerbil after ischemia/reperfusion insult.

The concentration of glutamate as well as the hydroxylation of salicylate, as an index of hydroxyl free radical formation, has been determined in the abdominal aorta and heart of gerbils undergoing an ischemia/reperfusion insult (IRI) and compared to control sham-operated gerbils. The amount of glutamate and hydroxylated salicylate (dihydroxybenzoic acid, DHBA) was significantly increased in both the aorta and heart of IRI-treated gerbils as compared to the aorta and in the heart of sham-operated gerbils. Vitamin E (90 mg/kg at 24 and 1 h prior to an IRI) pretreatment prevented the increase of both glutamate and DHBA in both the aorta and heart of IRI-lesioned gerbils. The results suggest that increases in glutamate, perhaps due to the decreased activities of glutamine synthetase, are correlated with increased oxygen free radical formation during an ischemia/reperfusion insult to the heart.