左心房血栓形成中血小板活化作用的研究

The role of platelet activation in left atrial thrombosis

目的:检测风湿性二尖瓣狭窄合并心房颤动的患者血浆P-选择素浓度变化,研究P-选择素蛋白及其在左心耳组织中的基因表达情况,探讨血小板活化在左心房血栓形成中的作用。方法:风湿性二尖瓣狭窄合并心房颤动患者80例(血栓组40例,无血栓组40例),健康人对照组15例(心脏移植供体10例取左心耳)。采用酶联免疫吸附剂测定法检测左心房及外周血浆P-选择素浓度。左心耳组织切片免疫组化染色,光镜下观察。实时荧光定量PCR对左心耳组织P-选择素基因表达进行定量研究。结果:与无血栓组相比,血栓组心房颤动时间更长、二尖瓣口面积更小、左心房内径更大,两组左心房内径均大于对照组。左心房与外周血P-选择素浓度差异均无显著性,血栓组外周血P-选择素浓度高于无血栓组,两组均高于对照组,免疫组化染色显示血管性血友病因子(vWF)和p-选择素蛋白在心内膜和心肌细胞中均有表达。左心耳组织P-选择素基因相对于正常左心耳组织的表达量,各组间差异无统计学意义性。结论:风湿性二尖瓣狭窄合并心房颤动患者血浆P-选择素浓度水平升高,外周血P-选择素浓度可代表左心房血中的浓度水平,血浆P-选择素浓度升高与P-选择素基因表达水平改变无关。

Objective：To study the changes of plasma level of P-selectin concentrations and the expression of P-selectin protein and gene in left atrial appendage（LAA） in patients with rheumatic mitral stenosis and atrial fibrillation（MS/ AF）.Methods：80 MS patients combined with AF（with LAT in 40 patients,without LAT in 40 patients） were studied.Blood specimens from 15 normal persons and LAA specimens from 10 donor hearts for heart transplantation were studied as control.The clinical data was collected.Blood samples were collected through peripheral vein and left atrium respectively during operation in MS/ AF patients.Only peripheral blood samples were collected in normal persons.LAA specimens were obtained during surgery.Enzyme linked immunosorbent assay method was employed to detect the plasma concentrations of P-selectin.The expression of P-selectin protein in LAA was studied with immunohistochemisty.Gene expression of P-selectin in LAA was studied using Real-Time Fluorescent Quantitative PCR.Results： Compared to patients without LAT,MS/AF patients with LAT had longer duration of AF,bigger left atrium dimension and smaller mitral valve orifice.The difference in plasma level of P-selectin between left atrium blood and peripheral vein blood was not significant in MS/AF patients.The peripheral plasma level of P-selectin in patients with LAT was significantly higher than those in patients without LAT and healthy individuals.The plasma level of P-selectin in patients without LAT was higher than that in healthy individuals.P-selectin protein was stained in both left atrial endocardium and cardiomyocytes.P-selectin protein stain was near the edge of cardiomyocytes.The difference of p-selectin gene expression in LAA among different groups was not significant.Conclusion： No difference in plasma level of P-selectin between left atrium and peripheral vein blood was observed.The increase of plasma level of P-selectin concentration was irrelevant to the change of expression of P-selectin gene.