Study On Platelet Activation Involving In The Pathogenesis Of Contrast-Induced Nephropathy Rat Model

Objective: To confirm that platelet activation involves in pathogenesis of contrast-induced nephropathy(CIN)via observing the expression of platelet membrane glycoprotein GPIIb/IIIa in the serum of rats subject to CIN.Meanwhile,interventional study with eptifibatide to determine the pertinence between GPIIb/IIIa,Kim-1 and NF-?B m RNA of renal tissue.The aim of this study is explore the role of platelet activation in the pathogenesis of contrast-induced nephropathy.Methods: 144 male Sprague-Dawley rats were allocated randomly to the following four equal groups(n=36/group):Normal control group(C),Eptifibatide control group(C+E),Contrast-induced nephropathy group(CM)and Contrast-induced nephropathy+Eptifibatide group(CM+E).CIN model group(CM)by tail vein injection of contrast agents(76% compound meglumine suffused with shade,10 ml/Kg),a total of 1 times.Normal control group(C)the tail vein injection of saline(10 ml/Kg).In accordance with the control group for the peptide(C + E)via tail vein by injecting saline(10 ml/Kg),injected for peptide(7.5 ml/Kg).For the peptide intervention model group(CM + E)via tail vein injection of contrast agents(76% compound meglumine suffused with shade,10 ml/Kg),then injected immediately in accordance with 7.5 mg/Kg for the peptide.Before the treatment,each rat eyeball blood 1 ml,after,after the treatment in 6 h,24 h,48 h,72 h,and 10 days time points,random death,6 rats in each group to collect blood and kidney specimens.Blood samples for biochemical detection(Scr,BUN,GPIIb/IIIa),renal tissue samples: 1)HE staining,used for kidney injury pathological grading;2)RT-PCR detection of kidney tissue NF-?B m RNA expression level;3)ELISA to detect the expression level of kidney tissue Kim-11.All data is represented as mean±standard deviation(x + s),using SPSS 17.0 software package for statistical analysis.Comparison between multiple sets of data,using the single factor analysis of variance(one-way ANOVA)or multiple factor analysis of variance(two-way ANOVA).If there are statistically significant,Student-Newmann-Keuls pairwise comparison(SNK)method.p < 0.05 represent statistically significant.Analysis ofthe expression of platelet membrane glycoprotein GPIIb/IIIa and pathological grading kidney damage,kidney expression and Kim-1 the NF-?B factor to express the relationship between the study of test using Pearson correlation analysis.Results:And in accordance with the normal control group for each test index of the peptide control group had no statistical difference in the corresponding time points.1,Serum SCr and BUN in CIN model group: the serum level of SCr in 6 h after building began to rise,peak at 48 h,the difference with the normal control group(P< 0.05),shows that building success;Starting from the 72 h SCr value gradually decline,to 10 days SCr value basic returned to normal,no statistical differences compared with normal control group(P > 0.05).Give for peptide after the intervention,CIN model group rats serum SCr value rise significantly decreased,but still higher than that of normal control group,there were significant differences in24/48/72 h time points(P < 0.05).BUN change trend was similar to SCr.2,Kidney tissue: Kim-1 in CIN model group,Kim-1 protein levels in building 6 h after began to rise rapidly,24 h peak namely,about numerical 5 times that of normal control group and normal control group with significant statistical difference(P < 0.05);Value decreased gradually from 48 h Kim-1,10 days basic returned to normal,no statistical differences compared with normal control group(P > 0.05).Give for peptide after the intervention,CIN model group rats Kim-1 the value rise significantly decreased,but still higher than that of normal control group,there were significant differences in 6/24/48/72 h time points(P < 0.05).3,Kidney injury pathological grading: CIN model group 6 h renal tubular injury(namely,24 h visible renal tubular epithelial cells,loss of brush border,cell degeneration,necrosis and regeneration,part of the renal tubular structure is damaged,the worst-hit medulla area,part of the renal interstitium is also a small amount of inflammatory cells infiltration and fibrosis formation,and normal control group with significant statistical difference(P < 0.05);48 h after renal tubular begin to repair,to 10 d basic returned to normal.CIN model group of renal damage of tubulointerstitium pathological score is significantly higher than the same point in time of the control group(P < 0.05).Give for peptide after the intervention,CINmodel group rats kidney injury pathological score high value declined,the difference compared with model group,but still higher than that of normal control group,there were significant differences in 6/24/48/72 h time points(P < 0.05).4,Kidney tissue NF-?B mRNA: after the modeling of kidney tissue NF-?B mRNA expression at each time point higher than the control group significantly(P <0.05),reached a peak at 48 h,then gradually drop back to normal levels.Give for peptide after the intervention,CIN model group kidney NF-?B mRNA expression level slightly decreased,compared with model group no statistical difference(P >0.05),but still higher than that of normal control group,there were significant differences in 6/24/48/72 h time points(P < 0.05).5,Platelet GPIIb/IIIa expression : In CIN model group,platelet GPIIb/IIIa expression level in building 6 h began to rise rapidly,after 24 h of the peak,and normal control group with significant statistical difference(P < 0.05);Starting from48 h platelet GPIIb/IIIa value gradually decline,to 10 days basic returned to normal,no statistical differences compared with normal control group(P > 0.05).Give for peptide after the intervention,CIN model group rats platelet GPIIb/IIIa rise significantly inhibited,but still higher than that of normal control group,in 24/48/72 h point was statistically difference(P < 0.05).6,Relevance between platelet membrane glycoprotein GPIIb/IIIa expression,kidney tissue Kim-1 and NF-?B mRNA expression:platelet membrane glycoprotein GPIIb/IIIa and kidney tissues,Kim-1 the NF-?B mRNA was significantly positive correlation,correlation coefficient r value were 0.9267,0.9267,and P values < 0.05.Conclusion: platelet activation is involved in the pathogenesis of CIN,inhibit ion of platelet activation can obviously improve the CIN model rat renal damage degree,part of the mechanism may be associated with the NF-?B mediated inflammatory pathways.