RESUMEN
Background: Histopathological lesions have been widely used as biomarkers for health evaluation of organism exposed to pollutants and can be used as warning symptoms for organism health. There are few reports regarding histomorphological changes in kidney following pesticide chlorpyrifos exposure which has prompted us to undertake this study. Methods: The present study was conducted on 45 inbred adult Wistar albino rats of either sex, weighing 145 – 165 gms. These animals were randomly divided into 3 groups A, B, C. Oral Chlorpyrifos was given to the experimental groups B and C in dose of 5 mg/kg body weight and 10 mg/kg body weight respectively. Group A served as control and was left as such. 3 animals from each group were sacrificed after 1 week, 2nd week, 4th week, 6th week and 8th week of initiation of experiment to see the histological changes in the kidney architecture. Results: Group A shows no histological alterations. Group B – No histological alterations in the kidney after 1 week. From 2 weeks-8 there was shrinkage of glomerulus at initial stages of treatment, tubular dilation, glomerular hypercellularity, hypertrophy of tubular epithelium, degeneration of renal tubules, deposition of eosin positive substance in the glomerulus and renal tubules. There were infiltration of lymphocytes in the interstitium and increased vascularity in the form of dilated vessels fibrosis and interstitial oedema. All these changes were suggestive of glomerulonephritis, acute tubular necrosis and interstitial nephritis leading to acute renal failure progressing to chronic renal failure with increasing duration. In Group C – the Kidneys of 1 week Chlorpyrifos treated rats exhibited shrunken glomeruli and hypertrophy of renal tubular epithelium. From 2nd week- 8thweek, the changes seen were more pronounced than Group B Conclusion: The present study showed that significant histomorphological changes were caused in the kidneys of rats administered with Chlorpyrifos. These changes were markedly different from the control rats. Hence this study brought into light the renal toxicity induced by chlorpyrifos which was found to be significant at high dose level.