Abstract:

To observe the change endoplasmic reticulum stress in renal injury of fluorosis rats, and explore the effect of endoplasmic reticulum stree in the mechanism of renal injury of fluorosis.Methods 48 Wistar rats were divided into 4 groups:control,fluoride-treated,low calcium,and low calcium plus fluoride-treated.The rats in fluoride-treated and low calcium plus fluoride-treated groups were treated with sodium fluoride (NaF,221 mg•L-1) through drinking water for 3 months.The  pathological  slice of rat kidney was made and the  morphological changes were observed under  optical microscope.The transcription levels of Grp78,Xbp1,CHOP and PDI in the  kidney ti
ssues were determined by reverse transcription-polymerase chain reaction (RT-PCR).Results Edema and vacuolar degeneration of the proximal tubule and distal tubule cells in the  kidney tissues in fluoride-treated group were observed;and cell edema
,vacuolar degeneration,scattered necrosis,minor regeneration repair and interstitial hyperemia in the kidney tissues in low calcium plus fluoride-treated group were found
.The mRNA expressions of Xbp1  in the kidney tissues in fluoride-treated  and low calcium plus fluoride-treated groups  were markedly higher than that in   the responding control groups（P<0.05）. The mRNA expression of Grp78     in the kidney tissues in low calcium plus fluoride-treated group  was　significantly increased   than that in  fluoride-treated and  low calcium groups（P<0.05 or  P<0.01）.The mRN
A expression of PDI   in the  kidney tissues in low calcium plus fluoride-treated group was significantly decreased than that  in  fluoride-treated group （P<0.05）;there was no significant difference in CHOP expression in the kidney tissues among 4 groups.Conclusion Overdosal fluoride can induce renal injury,and low calcium nutrition may  aggravate the toxicity of fluoride on kidney.Endoplasmic reticulum stress is likely involved in the pathogenesis of renal injury of fluorosis rats.

Key words: sodium fluoride;kidney;endoplasmic reticulum stress