EVALUATION OF THE AMELIORATIVE ROLES OF VITAMINS A, C AND E ON ASPARTATE AMINO TRANSFERASE (AST) PRODUCTION IN CLARIAS GARIEPINUS (BURCHELL, 1822) FINGERLINGS EXPOSED TO LEAD NITRATE

The presence of pollutants in the environment of an aquatic organism such as fish can lead to the production of reactive oxygen species and consequently, oxidative stress. The effects of lead nitrate on aspartate amino transferase (AST) in C. gariepinus and how such effects can be ameliorated through administration of vitamins were investigated. C. gariepinus fingerlings (whose initial weight ranged from 3-11g) were exposed to sub-lethal concentrations of Pb (00, 26mg/L, 44mg/L, 61mg/L and 79mg/L) with replicate in each case. 26mg/L of the vitamins in each case was administered across all bud. Fresh concentrations of both toxicant and vitamins were administered every 72 hours for a period of 12 weeks every time the water medium was changed. 3 samples of the fish were randomly selected and sacrificed from each aquarium tank every 2 weeks of the exposure period. The gills, kidneys and liver were excised from these specimens and homogenized in sodium phosphate buffer and then assayed for AST production levels in each case. From the results: In Pb only group samples, the highest mean values of AST in the liver and kidneys were obtained in T1. The highest AST in the gill was obtained in T4. In PbVA samples, the highest AST in the liver was obtained in T3. The highest AST produced in the kidneys was obtained in T2.The highest AST produced in the gill was obtained in T4. In PbVC, the highest AST values in liver and kidneys were obtained in T1. The gills’ AST had its highest in T4. In PbVE, the highest AST in the liver was obtained in T1. The highest AST produced in the kidney was obtained in T4. The highest AST in the gill was obtained in T2. The kidneys of the samples of the Pb only and PbVA groups recorded the highest. The liver and the gills in the PbVC and PbVE groups, respectively produced the highest values of AST. The high levels of production of the antioxidant suggests that AST is a good biomarker of the oxidative stress elicited by the presence of the toxicant