野百合碱预处理对大鼠右心室功能及规范性瞬时感受器电位亚家族表达的影响

Effects of Monocrotaline on Right Ventricular Function and Expression of Cardiac Canonical Transient Receptor Potential Channels Subfamily in Experimental Rats

目的:探讨腹腔注射野百合碱(MCT)3周对大鼠右心室功能的影响以及规范性瞬时感受器电位(TRPC)亚家族在野百合碱诱导的右心室心肌肥厚中的表达。方法:将20只SD雄性大鼠随机分为对照组(n=10)和野百合碱诱导右心室肥大模型组(MCT组,n=10)。MCT组以2%MCT 60 mg/kg剂量一次性腹腔注射,建立MCT诱导的右心室肥厚大鼠模型。3周后,分别测定以上两组的右心室血流动力学参数和右心室肥大指数(RVMI),右心室心肌病理切片,并通过逆转录多聚酶链反应(RT-PCR)和蛋白免疫印迹法(Western-blot)来检测信使核糖核酸(mR NA)和TRPC亚型的蛋白表达水平。结果:MCT组与对照组比较,右心室收缩压、RVMI显著升高,右心室内压力最大上升速率显著增加,右心室内压力最大下降速率显著下降,差异均有统计学意义(P<0.01);MCT组右心室心肌纤维增粗,细胞内肌原纤维数量增多,心肌纤维排列紊乱,细胞核深染,形状不整;MCT组较对照组右心室心肌组织TRPC6 mR NA表达升高,(n=6),右心室TRPC6蛋白相对表达水平升高(n=4),差异均有统计学意义(P<0.05)。结论:MCT预处理3周可诱导SD大鼠产生右心室心肌肥厚,上调了右心室心肌细胞TRPC6通道蛋白的mR NA和蛋白的表达,TRPC6可能参与了心肌肥厚的发生发展。

Objective： To explore the effects of monocrotaline （MCT） on right ventricular function and expression of cardiac canonical transient receptor potential channels （TRPC） subfamily in experimental rats. Methods： The SD male rats were randomly divided into 2 groups：Control group, the rats were normally fed and MCT group, the rats received a single dose injection of MCT 60 mg/kg to induce myocardial hypertrophy. n=10 in each group and all animals were treated for 3 weeks. The right ventricular hemodynamics parameters and right ventricular hypertrophy index （RVHI） were measured, right ventricular myocardium tissue section was observed by HE staining, the mRNA and protein expressions of TRPC subfamily were examined by RT-PCR and Western blot analysis. Results： Compared with Control group, MCT group had increased RVSP, RVHI, RV＋dp/dtmax and decreased RV-dp/dtmax, all P〈0.01. In MCT group, the right ventricular myocardial cells had the thinker ifber, deeply stained nuclei with irregular shape. Compared with Control group, the mRNA and protein expressions of right ventricular TRPC6 were elevated in MCT group, n=6 and n=4 respectively, all P〈0.05. Conclusion：Right ventricular hypertrophy could be induced by 3 weeks MCT treatment, it up-regulating the mRNA and protein expressions of TRPC6 which might be involved in the occurrence and development of cardiac hypertrophy in experimental rats.