Aspartate Transaminase (AST) Activity in Selected Tissues & Organs of Clarias Gariepinus Exposed To Different Levels of Paraquat

Analyzing the activities of aspartate transaminase in tissues can help detect tissue damage cause by toxicants such as paraquat. The activities of aspartate transaminase (AST) in some tissues and organs of Clarias gariepinus exposed to various levels of paraquat (2, 4, 6 and 8ppm) were studied for a period of thirty (30) days. The tissues and organs investigated include blood plasma, kidney, liver, gills and muscle. The result showed changes in AST activity in the treatment group as compared to the control group; however the increase was not concentration dependent. AST activity was highest in the liver (445.00 ± 0.00IU/L SD) and lowest in the gill (65.00 ± 27.39 IU/L SD) in the control group. There was no significant change in AST activity in the liver across the treatment range. AST activity however declined in the muscle with the lowest at 6ppm of paraquat. There was a significant increase in AST activity in the gills at 4ppm of paraquat, this later declined to almost control levels at higher concentrations. In the kidneys AST activity also significantly peaked at 4ppm of paraquat. This declined slightly and was maintained at higher treatment concentrations. AST activity peaked in the plasma at 4ppm of paraquat as well. This dropped slightly and picked up at 8ppm. Analyzing the activities of AST in tissues can help detect tissue damage cause by toxicants such as paraquat. It can consequently be inferred that AST activity can be used as a reliable biomarker for diseased condition in the plasma, gills and kidney but not the liver or muscle of Clarias gariepinus.