EFFECT OF MORPHINE AND NALOXONE ON OXIDATIVE-METABOLISM DURING EXPERIMENTAL RENAL ISCHEMIA AND REPERFUSION

During experimental renal ischemia and reperfusion in rabbits, morphin e as well as naloxone significantly inhibited the increased superoxide anion (O-2(-)) and generation by resting and opsonized zymosan-stimul ated phagocytes in renal venous blood. Morphine with naloxone in combi nation inhibited O-2(-) generation to a lesser extent than that observ ed when these drugs were used separately. Morphine and/or naloxone did not significantly affect erythrocyte superoxide dismutase (SOD-1), gl utathione peroxidase (GPx) and catalase activities or malonyldialdehyd e (MDA) concentrations in venous blood during renal ischemia. During r eperfusion there was a tendency to a slight reduction of erythrocyte c atalase activity in morphine-treated animals, and to slight diminution s of erythrocyte SOD-1 and GPx activities and erythrocyte MDA concentr ations in rabbits treated with naloxone and morphine in combination. T hese results indicate that opioid receptor agonists and antagonists mo dify the response of the kidney to acute injury. These effects may hav e relevance to the pattern of oxidative stress seen in patients with a cute ischemic renal failure.