The Role Of Osteopontin On Renal Injury Induced By Flurosis

Fluoride is a widely distributed nephrotoxin with exposure potentially resulting from environmental fluorine excess. Kidney is the main excretory organ of fluorine. The remarkable renal pathological changes were observed in rats treated by sodium fluoride (NaF), and the major damage induced by fluoride was renal tubules. Significant increase of fluoride caused renal fibrosis and renal tubules dilatation. The proximal renal tubular cells degeneration and necrosis associated with proliferation were observed when lower dose of fluoride was administered. A series of experiments was conducted to study the mechanism of NaF on renal tubules lesion. Different oral dose of NaF in aqueous solution was given to Wistar rats and cultured renal tubular cells in vitro to observe morphological and functional changes of renal cells and the role of oxidative stress in renal injury mechanism induced by over-dose fluoride, and expression and roles of osteopontin(OPN) and matrixmetalloproteinase-2(MMP-2)in kidney lesion of rats treated with NaF. This study sought to observed the following problems kidney injury caused by fluoride toxicity by means of pathological, biochemical, molecular biological techniques.The pathological examination showed that renal epithelial cells degenerated, and appeared intensely eosinophilic cytoplasm with dense nuclear chromatin fragments. The results of MTT method In vitro culture renal tubular cells showed that the proliferous activity changed from sightly to dramatically intensed in response to fluoride concentration from 0.1mg/L to 15mg/L, but renal tubular cells proliferation obviously decreased in the 25mg F-/L group. The study was to explored the effect of NaF on oxidative stress of kidney. The activity of renal GPX(glutathione peroxidase) in the 100mgF-/L group was obviously higher compared with the control. The activity of SOD(superoxide dismutase) greately increased in the low calcium +fluoride group, but the activity of GPX decreased in this group. The oxidative stress of cultured renal tubular cells revealed that the activity of SOD, CAT in the cells exposed to fluoride 24h group significantly increased, but the level of MDA showed descent trend. The activity of SOD in the cells exposed to fluoride 72h group decreased compared to...