Effects of sodium nitrate contaminated water on renal cortical tissue in adult male albino rats histological, histochemical and electron microscopy study

ABSTRACT

The wide use of nitrates and nitrites as preservatives in food technology and its presence in drinking water elevates the importance of studying their effects on mammals. The present study aimed to evaluate the histological and histochemical effect of these substances on the renal cortical tissue. Twenty adult male albino rats were used being divided equally into four groups, the first group served as a control and second, third and fourth groups were provided with sodium nitrate contaminated water at the concentration of 50, 100 and 300 mg/L respectively for 45 days. The study showed many histopathological alterations, the renal tubules were degenerated, the glomeruli were atrophied and marked increase in cellular infiltration were also noticed. As regard histochemical changes, the treated groups showed decreased polysaccharide, total protein, DNA, RNA and alkaline phosphatase enzyme while the acid phosphatase activity increased. Immunohistochemical staining showed negative Kappa light chain immunoglobulin and positive lambda light chain immunoglobulin in third and fourth groups. The chemical has induced certain destructive alterations in the fine structure of the renal cortex, the glomerular capillaries were dilated and their lumina were filled with flocculent materials and red blood cells beside fusion of the feet processes of podocytes and thickening of blood-renal barrier. The lining cells of the kidney tubules have also undergone prominent destruction with loss of a considerable number of their microvilli, the mitochondria have designated membrane damage, demolished ridges with tiny flocculent material in their interium Lysosomes were also increased in number. These destructive effects increased with increasing the concentration of the sodium nitrate in drinking water. It is concluded that, sodium nitrates had toxic effects on renal cortical tissue, so these substances must be forebidden as food preservatives and its concentration in drinking water must be at the least level to avoid these adverse effects