Effect And Mechanism Of Carbon Disulfide On Renal Tubular Epithelial Cell Apoptosis In Rats

Abstract:Objective:To investigate the effectand mechanismof different concentrations carbon disulfide?CS₂?on renal tubular epithelial cell apoptosis in rats.Methods:Thirty healthy male SD rats were selected,then randomly divided into five groups:the normal group,the control group?0 mg/kg?,the low CS₂ exposure group?50 mg/kg?,the middle CS₂ exposure group?150 mg/kg?,and the high CS₂ exposure group?250 mg/kg?,each group had six rats.Rats in the exposure groups were exposed to CS₂ by intraperitoneal injection for 16 weeks,five days a week,once a day,the CS₂ was dissolved into olive oil.The control group was given the same doseof olive oil,also by intraperitoneal injection.And had no deal with the normal group.Weighed every week at the fixed time and the doses were adjusted correspondingly according to the weight.At the end of 16th weekend,rats were taken to collect 24hurine samples,the urine protein and urine N-acetyl-?-D-gluosaminidase?NAG?were tested.Then all rats were sacrificed,and blood samples weredrawfrom heart,the serum creatinine?Scr?and urea nitrogen?BUN?were tested,the kidney index was calculated according to specific formula.Pathological changes of renal tissues were observed by HE staining under light microscope.The apoptosis of nephrocyte was measured by TUNEL method,and the expression of apoptosis inducing factor?AIF?,Bax,Bcl-2,cytochrome c?Cyt c?,cysteinyl aspartate-specific protease 9?Caspase-9??cysteinyl aspartate-specific protease 3?Caspase-3??cysteinyl aspartate-specific protease 8?Caspase-8?proteins in the renal tissue were detected by immunohistochemical method.Results:?1?Compared with the normal group and the control group,the urine NAG of exposure groups were increased obviously?P<0.05?.And theurine NAG of the high dose group were significanthigher than that of the low dose group and the middle dose group?P<0.05?.Compared withthe normal group and the control group,the Scr and BUN of the middle dose group and the high dose group were increased obviously?P<0.05?,but there had no significant increasein the low dose group?P>0.05?.The Scr and BUN of the high dose group were significant higher than that of the low dose group?P<0.05?.There had no obvious difference ofurineprotein in all groups?P>0.05?.Compared with the normal group and the control group,the loss of weight and the increase of kidney index in the high dose group and the middle dose group were obviously?P<0.05?,but there had no obvious change in the low dose group?P>0.05?.Compared with the low dose group,the change of weight and kidney index in the high dose group was obviously?P<0.05?.?2?Renal pathological changes:there had no obvious abnormal of the renal tissues in the control group and the normal group.But the renal tubulesof exposure groups appear in different degree of injury,the pathological grading of the injured renal tubule was higher in exposure groups than that in the normal group and the control group?P<0.05?,and the extent of injurywas increased with increased dosage?P<0.05?.?3?Renal cell apoptosis:the apoptosis cells were mainly in the renal tubules,the apoptosis index of the exposure groups were significant higher than that ofthe normal group and the control group?P<0.05?,and increased with increased dosage?P<0.05?.?4?The expression of apoptosis related proteins:apoptosis-related proteins such as Bax,Bcl-2,Cyt c,Caspase-3,Caspase-9 were mainly expressed in renal tubular epithelial cells,and had no obvious expression in glomerulus.The expression of Bax,Cyt c,Caspase-3,Caspase-9 proteinsin the exposure groups were significant higher than that inthe normal group and the control group?P<0.05?,and increased with increased dosage?P<0.05?.The expression of Bcl-2 in the exposure groups was significant lower than that in the normal group and the control group?P<0.05?,and reduced with increased dosage?P<0.05?.Compared with the normal group and the control group,the Bax/Bcl-2 ratio of the exposure groupsincreased obviously?P<0.05?,and increased with increased dosage?P<0.05?.The expression of AIF and Caspase-8 had no significant difference in all of the experimental groups?P>0.05?.Conclusion:1.CS₂ can cause renal tubuleinjury;2.Apoptosis is one of the mechanisms of renal tubule injury caused by CS₂.3.Mitochondrial pathway is involved in the renal tubular epithelial cell apoptosis caused by CS₂.