Quantitative study of the histopathological effects of sodium arsenite on kidney stracture in rats

Sodium arsenite is an environmental pollutant which its amounts in industrial cities are more than other places because of its use in chemical industry. Human populations are exposed to this chemical compound through food, soil, air and water which has toxic and histopathological effects on different body organs including kidney. The aim of this investigation is to study the quantitative histopathological effects of sodium arsenite on the kidney structure of rats. 12 male Wistar rats with mean body weight of 200±20 g were randomly divided into 2 groups (n=6). One treated with sodium arsenite (8 mg/kg/day in drinking water) and the other one (the control group) received drinking water only. 2 months after treatment the rats were weighed, anesthetized with ether and dissected. The left kidney was taken out, cleaned, weighed and then fixed in 10% formaldehyde solution. After obtaining 1mm thick slices, tissue processing was carried out, then 5µm thick sections were prepared and stained using H&E method. Slides were finally studied stereologically and data was statistically analyzed using paired sampled t-test and the means were considered significantly different at p<0.05. The results of this investigation indicated significant reduction in the total mean volume of kidney (p<0.001), cortex (p<0.001), and medulla (p<0.003) in sodium arsenite treated group compared to the control rats. The mean volume of tubules and interstitial tissue as components of cortex reduced significantly compared to the control group (p<0.003).The mean volume of glomeruli and Bowman's capsule was significantly reduced in treated group (p<0.001), while the other components did not show a significant reduction in volume. A significant reduction was also found in the kidney (p<0.002) and the body weight (p<0. 01) in the treated group compared to the control ones at the end of the experiment. It was concluded that exposure to sodium arsenite leads to histopathological changes in kidney structure, however more studies are needed to determine the effects of these structural changes on the kidney function.