IMMUNOMODULATORY EFFECTS OF ORNITHINE ALPHA-KETOGLUTARATE IN RATS WITH BURN INJURIES

Objective: To investigate the influence of enterally administered orni thine alpha-ketoglutarate (OKG) on muscular amino acid content, eicosa noid release, and polymorphonuclear leukocyte responsiveness after ind uction of burn injury in rats. Design: Experimental trial. Materials a nd Methods: Four groups of rats were considered: (1) healthy rats that received a standard diet supplemented with 5 g/kg per day of OKG; (2) rats with burn injuries that received the same nutrition as group 1; (3) healthy rats that received a standard diet supplemented with glyci ne in an isonitrogenous amount relative to OKG; and (4) rats with burn injuries that received the same nutrition as group 3. The thymus and 1 skeletal muscle were weighed. The oxidative metabolism of pleural po lymorphonuclear leukocytes was measured by means of superoxide generat ion (O-2(-)) and the chemiluminescent response to opsonized zymosan. P rostaglandin E(2) and 6-keto-prostaglandin F-1 alpha were measured in the supernatants of pleural and peritoneal cells. Results: The weights of the thymus and the muscle from healthy rats were similar. Those of rats from group 4 were significantly lower (P<.05), whereas those of rats from group 2 were not. Metabolism of OKG led to enhanced amounts of arginine and glutamine in skeletal muscle. The metabolic bursts of polymorphonuclear leukocytes from healthy rats were similar. Those of glycine-treated rats with burn injuries were significantly depressed ( P<.05), whereas those of the OKG-treated group were not. Pleural and p eritoneal cells from the rats with burn injuries that received OKG gen erated significantly more prostaglandins (P<.01) than did cells from t he other groups of rats. Conclusion: Ornithine alpha-ketoglutarate adm inistered to rats with burn injuries displays immunomodulatory propert ies that can enhance host-defense mechanisms in animals that are affec ted by a severe injury.