Nature Environment and Pollution Technology

M. Venkata Chandrudu ¹, K. Radhakrishnaiah ¹

Affiliations
1 Department of Zoology, Sri Krishnadevaraya University, Anantapur-515 003, A.P., IN

Abstract

Histopathological studies would help in evaluating the extent of damage caused to the tissues under stress. Hence, in the present study an attempt has been made to observe the structural changes in the hepatopancreas and foot of the mussel Lamellidens marginalis exposed to acute (11.0mg/L) and subacute (1.10mg/L) concentrations of cadmium. The changes are observed at day 1 and day 3 in acute concentration and day 10 and 30 in subacute concentration, one at short- term and the other at long-term exposure. In hepatopancreas enlargement of intertubular area, cell necrosis and the formation of sinuses and in foot loss of connective tissue, vacuolization, disarrayed fibres and nuclear pyknosis were seen on exposure to acute concentration of cadmium at day 1. Similar changes with mild degree of recovery were observed at day 3. In subacute concentration some degenerative changes like mild tubular atrophy and cell necrosis in hepatopancreas and fibrillation, intermuscular oedema and pyknotic nuclei in foot of mussel were observed at day 10, however, at day 30 the tissues appeared more or less similar to those of controls with insignificant changes.

Keywords

Heavy metals, Cadmium Toxicity, Lamellidens marginalis, Hepatopancreas, Histology, Degenerative changes, Cell Necrosis, nuclear pyknosis, Fibrillation.

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M. Venkata Chandrudu ¹, A. Sreenivasa Reddy ¹, K. Radhakrishnaiah ¹

Affiliations
1 Department of Zoology, Sri Krishnadevaraya University, Anantapur-515 003, A.P, IN

Abstract

The levels of pyruvate and lactate, and the activities of succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) were estimated in the organs of freshwater mussel Lamellidens marginalis and fish Labeo rohita at days 10, 20 and 30 after exposure to the subacute (0.7 mg/L) concentration of cadmium. A decrease was observed in succinate dehydrogenase (SDH) activity along with a corresponding decrease in pyruvate level with an increase in lactate dehydrogenase (LDH) activity and lactate level in ctenidium, mantle, hepatopancreas and foot of the mussel and in the kidney, liver and muscle of the fish at all the days of exposure. Interestingly, an increase was observed in SDH activity and pyruvate level with a decrease in LDH activity and lactate levels in the gills of the fish. Among the exposure periods, either the percent suppression or elevation progressively recovered and reached to near normal over time of exposure in the order: day 10>20>30 in the organs of mussel. Whereas, in the organs of fish it was in the order: day 10>20<30. Thus, between the two groups of animals, either the percent suppression or elevation was progressively recovered over time of exposure in the organs of mussel, but the fish exhibited a little recovery at day 20 with a significant fall at day 30. These results indicated an adaptive ability to subacute concentration of cadmium in the organs of mussel by normalizing the oxidative and glycolytic pathways on prolonged exposure; whereas the fish exhibited susceptibility due to the suppression of oxidative metabolism and increased dependency on anaerobic glycolysis.

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