A study on the toxicity of cadmium on certain aspects of protein metabolism of the freshwater mussel Lamellidens marginalis (Lamarck) and freshwater fish Labeo rohita (Hamilton)

ABSTRACT The activities of alanine and aspertate aminotransferases (AlAT and AAT) and glutamate dehydrogenase (GDH) and the levels of glutamine are estimated in the organs of mussel and fish exposed to subacute concentration of cadmium (0.7 mg/l) and controls. The AlAT, AAT and GDH activities and glutamine level increased relative to controls in ctenidium, mantle, hepatopancreas and foot of mussel in the order: day 10 > 20 > 30. Whereas in gill, kidney, liver and muscle of fish the activities of AlAT and AAT increased at day 10 and 20 (day 10 > 20) with a decrease at day 30. GDH activity and glutamine levels, however, increased at all the days in the order day 10 > 20 < 30. Increased transamination was observed in the organs of mussel on initial days of exposure, but they reached to normal at day 30. In fish even though an initial increase trans-deamination was observed at day 10, it tried to recover at day 20 but failed to attain recovery on further exposure. Among the organs the degree in all the changes of protein metabolism was more or less insignificant and inconsistent, but in general it was in the order hepatopancreas > ctenidium > foot > mantle in mussel and kidney > liver > gill > muscle in fish. The results indicated that in sublethal cadmium stress the mussel gradually attained normal protein metabolic activity on prolonged exposure to 30 days but the fish could sustain upto day 20 later it became susceptible as indicated by more suppressive changes at day 30