Bioassay of cadmium and its effect on differential distribution of dehydrogenases in different brain regions in Labeo rohita (HAM).

The sublethal effect of cadmium on the specific activities of lactic, malic and succinic dehydrogenases in different brain regions in Labeo rohita (HAM) was assessed with reference to acute, chronic and recovery conditions. Cadmium enhanced succinic, malic and lactic dehydrogenases to a marked extent in the cerebrum from 0 to 12 h exposure. However, a subsequent fall of the above enzymes in some regions was recorded from 12 to 24 h. In chronic studies, the greatest decrease in succinic dehydrogenase was noted in the cerebrum (0 to 15 days) and the least reduction in the cerebellum (30 to 45 days) in comparison with malic and lactic dehydrogenase. In recovery studies an optimum rise in lactic, malic and succinic dehydrogenase was found in the cerebrum (30-45 days). In general, cadmium accumulation was highest in the cerebrum (12 h and 15 days) and least in the cerebellum (24 h and 45 days). This was markedly above the safety level in acute and chronic situations.