Oxidative stress is one of the major factors involved in the pathogenesis of adriamycin-induced cardiac dysfunction. The present study examined the antioxidant defense of glutamine on myocardial antioxidant status in adriamycin-induced cardiomyopathy in rats with respect to changes in the levels of lipid peroxidation and reduced glutathione, and the activities of antiperoxidative enzymes [superoxide dismutase (SOD) and catalase (CAT)] and glutathione dependent antioxidant enzymes [glutathione peroxidase (GPx) and glutathione-S-transferase (GST)] in the heart tissue. Intraperitoneal injection of adriamycin caused a significant (P<0.001) rise in the level of lipid peroxidation in the heart tissue with a concomitant (P<0.001) decline in the level of reduced glutathione and the activities of the antioxidant enzymes. Oral administration of glutamine significantly (P<0.001) ameliorated these adriamycin induced adverse effects and maintained the level of the evaluated parameters nearly at normal. The results of the present investigation demonstrated that the protective effects of glutamine against the toxicity of the prooxidant antitumor drug, adriamycin, might be attributed at least partially to its antioxidant properties.

Key words: Glutamine, adriamycin, cardiomyopathy, lipid peroxidation, reduced glutathione, antioxidant enzymes.