Effect of Ambient and Dietary Cadmium on Pavement Cells, Chloride Cells, and Na+/K+-Atpase Activity in the Gills of the Freshwater Teleost Oreochromis Mossambicus at Normal and High Calcium Levels in the Ambient Water
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Date
1993
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Publisher
Elsevier
Abstract
The effects of cadmium on the gills of the African freshwater cichlid Oreochromis mossambicus in water with normal and relatively high calcium concentrations were studied for periods up to 35 days. The exposure was either through the ambient water or via the diet. Changes in the ultrastructure of the gill epithelium upon exposure to cadmium in the ambient water indicated degeneration of pavement cells and chloride cells, and acceleration in the turnover of the chloride cells. Studies of the Na+/K+-ATPase activity of the gills indicated that a transient increase in the total number of chloride cells was not associated with an increase, but rather a decrease of the total ion-exchange capacity of the chloride cells. Macrophages, lymphocytes, rodlet cells and neutrophilic granulocytes infiltrated the filament epithelium. Recovery of the gills was observed after 35 days. Dietary cadmium caused similar, although delayed, effects. High water calcium concentration reduced the impact of water-borne cadmium, but had no ameliorating effect on dietary cadmium. The data indicate that the disturbance of ion regulation in fish caused by sublethal levels of dietary cadmium is the result of effects of the metals on the gills rather than on the kidney.
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Keywords
Calcium, Water-borne cadmium, Dietary cadmium, Gills, Na+/K+-ATPase activity, Oreochromis mossambicus
Citation
Pratap, H.B. and Bonga, S.W., 1993. Effect of ambient and dietary cadmium on pavement cells, chloride cells, and Na+/K+-ATPase activity in the gills of the freshwater teleost Oreochromis mossambicus at normal and high calcium levels in the ambient water. Aquatic Toxicology, 26(1), pp.133-149.