盐敏感性高血压大鼠eNOS、iNOS表达与心肌细胞凋亡关系分析

目的探讨盐敏感性高血压形成和心肌细胞损害产生的机制。方法以辣椒辣索损伤Wistar大鼠感觉神经，饲喂高盐饲料，建立盐敏感性高血压大鼠模型。苏木素～伊红染色观察大鼠组织病理学改变；分光光度法检测心肌组织iNOS活性和NO含量；免疫组织化学方法检测心肌eNOS、iNOS蛋白表达；RT．PCR检测心肌eNOS、iNOSmRNA的表达。单细胞凝胶电泳检测心肌细胞凋亡。结果实验结束时各组比较体重无显著性差异（P〉0．05）。在第2、3、4周时，辣椒辣素高盐组鼠尾收缩压与对照组相比差异显著（P〈0．05）。辣椒辣素高盐组心肌细胞排列紊乱、细胞间隙明显增大，细胞核排列不整齐；心肌iNOS、NO水平升高（P〈0．05）；eNOS蛋白表达减少（P〈0．05）与eNOSmRNA表达减少（P〈0．01）；iNOS蛋白表达和iNOSmRNA表达显著增高（P〈0．01）；凋亡细胞数升高（P〈0．05）。结论eNOSmRNA和蛋白的低表达与感觉神经损伤性盐敏感性高血压大鼠形成相关。iNOSmRNA和蛋白的高表达及iNOS活性升高使心肌组织局部产生大量NO。NO可能使得感觉神经损伤性盐敏感性高血压大鼠心肌细胞凋亡增加，从而加重心肌的损伤。

Studies on the Expression of eNOS,iNOS and Heart Apoptosis in Salt-Sensitive Hypertensive Rat

Objective To propose the formation of salt-sensitive hypertension and heart cell damage. Methods Wistar rats, capsaicin was injected and high salt diet was feeded, the model of salt-sensitive hypertension was established. the change of heart histopathology were observed, spectrophotometry to detect heart iNOS activity and NO content; immunohistochemistry was performed to detect the expression of eNOS and iNOS protein in heart, the expression of eNOS and iNOS mRNA in heart was determined by RT-PCR, the level of apoptosis was assessed by single cell gel electrophoresis. Results The rats body weight was not significant difference among groups at the end of the experiment （P 〉 0.05）. The capsaicin-high salt diet group systolic blood pressure was significantly higher than the other three groups （P 〈0.05） in 2, 3, 4 weeks. Capsaicin-high salt diet group cardiac muscle cell hypertrophy, muscle fiber disarrangement, nuclei arranged in irregular. The activity of iNOS and level of NO in capsaicin-high salt diet group significantly were higherwhen compared with control group, eNOS protein and eNOS mRNA significantly decreased compared with control group （P 〈 0. 01 ） iNOS protein and iNOS mRNA of capsaicin-high salt diet group were significantly increased compared with control group （P 〈 0.01 ） in heart. The number of apoptotic cells of capsaiein-high salt diet group significantly increased compared with control group （P 〈 0. 05）. Conelttsions The decreased express of eNOS mRNA and protein was related with the forming of salt-sensitive hypertension. The increased express of iNOS mRNA and protein could produce a large number of NO in heart. NO may make the cell apoptosis increasing and the damage of heart in salt-sensitive hypertensive rats.