Effects Of Different Concentrations Of Peritoneal Dialysis Fluid On ET-1,ETAR And ETBR Expression Of CAPD Rat Peritoneum

Objections:Endothelin -1(ET-1),a 21-amino peptide hormone,has potent vasoconstrictor activity which also induces production of extracellular matrix proteins and involves in fibrotic processes of numerous organs.These ET-1 effects are elicited through the activation of two receptor subtypes,ETAR and ETBR.In the present study,we detected the expressions of ET-1,ETAR,ETBR and FN in peritoneum treated with different concentrations of PDF through the rat CAPD models,and then to investigate the effect of PDF on ET-1,ETAR,ETBR,FIg and analyze the relationship of ET-1,ETAR,ETBR and FN in non-infection situations to gain a better understanding of the mechanism of CAPD related peritoneal fibrosis.Methods:Experiments were performed on 40 adult male Sprague-Dawley rats weighing between 280～350g.Rats were randomized into 4 groups randomly and received daily intraperitoneal injection of 20ml 1.5%,2.5%,4.25%PDF into the respective group for 4 weeks except the control group,on the 29th day,after a 4-hour dwell,the rats were put to death,parietal peritoneum tissue were taken to determine the ET-1,ETAR,ETBR and FN protein expression by immunohistochemistry.Results:1.The expression of ET-1,ETAR,ETBR and FN in experimental groups was higher than that of control group,and the differences were significant.The ET-1, ETAR,ETBR and FN protein expression in 4.25%group were the highest of the experimental groups,and the values of 2.5%group were higher than that of 1.5% group.2.The ET-1,ETAR and ETBR protein in 4.25%group were higher than that of 1.5%group and 2.5%group,and the differences between 4.25%group with 2.5%group,4.25%group with 1.5%group were statistically significant(P＜0.05), but the differences between 2.5%group with 1.5%group had no statistic significance(P＞0.05).3.The FN protein expression in 4.25%group were higher than that of 2.5%group, and the values of 2.5%group were higher than that of 1.5%group,and the differences of the 3 groups had statistic significance(P＜0.05).4.There were positive correlations between expression of ET-lor ETAR or ETBR and FN(r=0.960,p＜0.01;r=0.908,p＜0.01;r=0.934,p＜0.01).Conclusion:1.PDF could induced the increase of ET-1,ETAR,ETBR and FN protein expression of CAPD rat peritoneum,and the increase followed by the increase of glucose concentrations of PDF.2.Accumulation of FN was associated with the increase expression of ET-1, ETAR and ETBR,so we can conclude that the increase expression of ET-1, ETAR and ETBR may be one of the reasons for CAPD relative peritoneal fibrosis.3.The increased expression of ET-1,ETAR and ETBR induced by glucose may be one of the reasons that glucose induce FN incresing.