地高辛抗体对大鼠再灌注心肌NO系统的影响

Effect of anti-digoxin antiserum on MIR-induced NO system injury of rats

目的观察心肌缺血/再灌注(myocardial ischemiareperfusion,MIR)时大鼠心肌组织,血清NO水平及NOS同工酶蛋白表达的变化和内洋地黄素特异性抗体对MIR时心肌NO系统损伤的保护作用。方法采用左冠状动脉前降支结扎30 min,复灌45 min建立在体大鼠MIR模型,Sprauge-Dawley大鼠随机分成7组,每组10只,假手术组、缺血/再灌注模型组、生理盐水组、维拉帕米组、小剂量、中剂量、高剂量地高辛抗血清组。各组于再灌注45 min后立即取左室心尖部缺血区心肌并断尾取血,检测心肌匀浆和静脉血中NO含量,心肌匀浆中的eNOS、iNOS水平,免疫组织化学SABC法检测心肌组织eNOS、iNOS;光镜下观察心肌组织形态学变化。结果MIR时心肌组织NO水平明显降低,但血清中NO水平无明显变化;eNOS表达明显减少,iNOS表达明显增加,心肌组织结构发生明显损伤;中、高剂量地高辛抗血清能有效降低心肌组织iNOS表达,恢复心肌细胞eNOS活性,提高心肌组织和血液中的NO水平,减轻MIR导致的心肌组织结构损伤。结论内洋地黄素特异性抗体对MIR造成的心肌NO系统损伤具有明显的保护作用,其作用机制可能通过拮抗内洋地黄素,调节心肌NOS同工酶的表达紊乱而实现。

Ahn To investigate the changes of myocardial NO levels and the expression of NOS isoforms in rats with myocardial ischemia/reperfusion （MIR）. The protective effect of anti-digoxin antiserum, an digoxin specific antagonist,on MIR-induced NO system injury. Methods Myocardial ischemia reperfusion injury models were obtained by ligating left anterior descend- ing coronary artery 30 min followed by 45 min reperfu- sion. Sprauge-Dawley rats were randomly divided into seven groups with 10 rats in each including sham group, MIR group, normal saline group, verapamil group, low dose, middle dose and high dose anti-digoxin antiserum group. NO levels of myocardial and serum, and activities of eNOS, iNOS were measured. The ex- pressions of myocardial eNOS, iNOS were determined by immunohistochemisry. Myocardial morphology was observed under optical microscope. Results Myocardial NO levels were significantly increased; serum NO levels did not change significantly; eNOS expression was significantly decreased; iNOS expression was sig- nificantly increased. Meanwhile, myocardial morphology injury was remarkable. With the intervention of middle and high dose anti-digoxin antiserum, expression of my- ocardial iNOS was significantly depressed; eNOS ex- pression was drastically elevated;serum and myocardial NO levels were significantly increased, The myocardial histological morphology was significantly improved. Conclusions Anti-digoxin antiserum could protect the function of myocardial NO system against MIR. The mechanism maybe associated with antagonizing endoxin and regulating the expression of NOS isoforms in myocardium.