Abstract
ABSTRACTThe aim of this work was to investigate whether the free radical scavengers, L-arginine (L-arg) and/or carnosine, either alone, or in combination would modulate tissue injury induced by hypoxia by measuring Fischer's ratio [concentrations of branched chain amino acids (BCAAs)/aromatic amino acids]. Decreased Fischer's ratios and increased malondialdehyde (MDA) led to pathogeneses of many diseases. Rats were injected with sodium nitrite (60 mg/kg) to establish hypoxia. They were treated with L-arg, (200 mg/ kg) and/or carnosine (200 mg/ kg) and their combination 24 and 1 h prior to sodium nitrite intoxication. The results revealed that hypoxia significantly decreased hemoglobin, arginine, citrulline and proline and increased sLDH, MDA , ammonia , urea, BCAAs (valine, leucine and isoleucine) and aromatic amino acids (phenylalanine and tyrosine ). The Fischer's ratio was decreased compared with the control; the administration of the aforementioned antioxidants ameliorated most of the previously altered parameters. It was concluded that Fischer's ratio was a valuable tool for understanding the pathology of hemic hypoxia, evaluating the degree of the modulatory effect of various natural antioxidants and the synergy between L-arg and carnosine in ameliorating the effect of sodium nitrite on amino acids pattern. Thus, it could be recommended to administer the combination of L-arg and carnosine in the areas of high altitudes to combat the hazard effect of hypoxia on hemoglobin concentration and MDA level.