Impairment of renal structure and function following heterogeneous chemical mixture exposure in rats.

Renal structural and functional alterations following an exposure to a heterogeneous chemical mixture (HCM) of phthalic acid di butyl ester, 1, 2–dichlorobenzene, cadmium chloride and chromium trioxide, administered through oral gavage in low doses (1/100 and 1/1000 of LD50 value of individual chemical) for 60 days, followed by withdrawal till 120 days resulted in significant rise in kidney lipid peroxidation and fall in the activities of enzymatic antioxidants. However, withdrawal of HCM treatment restored most of these altered parameters. Degenerative changes in the kidney included proximal convoluted tubules devoid of brush boarder with cytoplasmic blebbing, dissolution and sloughing of nuclei. Cortical glomeruli were also affected with epithelial disintegration, pyknosis of podocyte nuclei and mesengial cell hyperplasia. The morphological alterations recovered fully in the low dose compared to the high dose treatment group.

Changes in selected biomarkers in freshwater teleost fish, Cyprinus carpio var. communis exposed to sublethal concentrations of chromium sulphate toxicity.

The toxicity of chromium sulphate on plasma electrolytes (Na+, K+, Cl-) level and Na+, K(+)-ATPase activity of an economically important fish, Cyprinus carpio var. communis was evaluated. During sublethal treatment, plasma sodium level was increased, whereas plasma chloride level decreased throughout the experimental period. Plasma potassium level increased upto 10th day and then declined in the rest of the study period. The Na+, K(+)-ATPase activity decreased upto 15th day of treatment and slowly recovered showing significant increase upto 25th day of treatment. The significant changes in the plasma electrolytes levels and Na+, K(+)-ATPase activity can serve as a valuable biomarker of pollutant exposure and effects.