In vivo effects of cadmium on some enzyme activities in tissues of the freshwater catfish, Heteropneustes fossilis

Abstract

Alterations in the activities of some enzymes in a freshwater catfish, Heteropneustes fossilis, have been examined in liver, kidney, intestine, ovary, gills, and muscles after exposure to 0.26 mg/liter of cadmium for 15, 30, and 60 days. The fish were hyperglycemic and hyperlactemic after 15 and 30 days of exposure. The liver and muscle glycogen content was depleted in the first two periods of exposure. In contrast, 60 days of cadmium treatment increased the glycogen content of the two tissues. Liver lactic acid level was elevated after 15 days. Muscle lactic acid content fell significantly after 15 and 60 days of exposure, but it was elevated after 30 days. Acid phosphatase activity was inhibited in liver, ovary, and gills but the enzyme activity increased in kidney and intestine. The activity of alkaline phosphatase decreased in liver, kidney, and intestine but elevation was recorded in ovary and muscles. In all three exposure periods, hexokinase activity of kidney and ovary was inhibited but the enzyme activity increased in intestine. Hexokinase showed elevation in liver, gills, and muscle after 15 and 30 days of exposure and inhibition after 60 days of exposure. The activity of xanthine oxidase decreased in liver and muscles and elevated in the rest of the tissues. Glutamate dehydrogenase fell significantly in intestine, ovary, and gills. In liver, kidney, and muscles the enzyme activity was elevated. Liver, intestine, gills, and muscles showed elevation in aminoacid oxidase activity. However, the enzyme activity was inhibited in kidney and in ovary.