Histopathological Changes Observed in the Kidney of Freshwater Fish, Cirrhinus Mrigala (Hamilton) Exposed to Cypermethrin

Abstract

The present study is aimed to assess the histological damage caused to the fish Cirrhinus mrigala exposed lethal (5.13 μg/l) and sublethal (1.026 μg/l) to pyrethroid derivative cypermethrin. Light microscopic studies exhibited sever histopathological changes in the kidney. The first sign of morphological changes in the kidney after injection of cypermethrin was found in the proximal tubule. Initial changes of these tubules included: deformation of brush border, gradual atrophy of basal cytoplasm and condensation of nuclear material. Following these initial changes, there was focal necrosis of tubular cells and pyknosis of nuclei. Degenerated cells were frequently seen extruding into the lumina of tubules, which were filled, with fragments of cellular components. Focal degeneration of tubular cells was usually followed by more extensive necrosis of the whole nephron. As the focal areas of necrosis became more widespread, more and more leucocytes and macrophages surrounded the tubules. Thus the area of interstitial tissue containing leucocytes and macrophages seemed to be increased as the tubules became reduced.