Inhibition of ATPase activity in the freshwater fish Labeo rohita (Hamilton) exposed to sodium cyanide.

Present study concerns the effect of sodium cyanide on the Indian major carp, Labeo rohita. Fishes were exposed to lethal (0.32 mg/L) and sublethal (0.064 mg/L) concentrations of sodium cyanide. The effect of intoxication was studied on Na(+)K(+)ATPase, Mg(+2)ATPase and Ca(2+)ATPase in various physiological tissues (gill, liver, and muscle) at the end of 1, 2, 3 and 4 days of lethal and 5, 10 and 15 days of sublethal exposure periods. Sodium cyanide induced significant inhibitory effects on the ATPase activity of the fish. Inhibition of the ATPase blocked the active transport system of the gill epithelial as well as chloride cells, and thus altered the osmo-regulatory mechanism of the fish. The value of the measured responses as an indicator of stress caused by water contamination discussed. The results confirm that ATPase levels significantly decreased in treated fish, indicating that ATPases could be used as sensitive and useful biomarkers for cyanide pollution.