兔右室流出道室速对L型钙通道α1c蛋白表达的影响

The Experimental Study of the Expression of L-type Ca^(2+) Channel Alpha 1c Protein in Right Ventricular Outflow Tract Ventricular Tachycardia in Rabbit

目的:通过建立右室流出道室速(RVOT-VT)的动物模型,以L型钙通道α1c蛋白作为观察指标,观察RVOT-VT时对L型钙通道α1c蛋白表达的影响,旨在探讨L型钙通道在RVOT-VT中的作用。方法:健康新西兰大耳白兔30只,随机分三组,分别为对照组(10只)、室速组(10只)、室速加维拉帕米干预组(10只)。采用免疫组织化学的方法对三组实验动物的右室流出道心肌组织进行L型钙通道α1c蛋白表达的检测。结果:1、高频刺激主动脉与肺动脉交界处均诱发了起源于右室流出道部位的室速,且室速持续时间均大于4小时。2、室速组L型钙通道α1c蛋白表达量明显下降;干预组L型钙通道α1c蛋白的表达下降,但与对照组比较无显著差异。结论:1、室速组的心肌L型钙通道α1C蛋白表达发生了重构。2、维拉帕米可以改善心肌L型钙通道α1C蛋白的重构。3、L型钙通道在RVOT-VT发生、持续中起重要作用。

Objective： To investigate the changes of L-type Ca2＋channel alpha 1 c subunit levels and distribution in rabbit with right ventricular outflow tract （RVOT） tachycardia induced by high frequency stimulation of sympathetic nerve at the epidium juncture of aorta and pulmonary artery. Further to clarify the mechanisms of electrical remodeling of right ventricular outflow tract （RVOT） tachycardia. Methods： The animal grouping： the rabbits were randomly divided into 3 groups：control group （n=10）, ventricular tachycardia （VT） group （n=10） and ventricular tachycardia＋verapamil group （n=10）.The rabbits were given high frequency （50ms, 5.0V） stimulation of sympathetic nerve at the epidium juncture of aorta and pulmonary artery to induce ventricular outflow tract tachycardia. Myocardium were dislodge of right ventricular outflow tract instantly after the death of the rabbits. The expression of L-type Ca2＋ channel alpha lc subunit in ventricular myocardium was studied by immunohistochemical technique. Results： 1.High frequency stimulation of sympathetic nerve at the epidium juncture of aorta and pulmonary artery can induce outflow tract ventricular tachycardia;which the duration was greater than 4 hours.2.The L-type calcium channel α1c subunit significantly decreased in ventricular tachycardia （VT） group, which also decreased in ventricular tachycardia＋verapamil group,but there was no significant difference compared with control group. Conclusion： 1. The L-type calcium channel α1c subunit was remodeled in the right ventricular outflow tract myocardium of rabbit with right ventricular outflow tract （RVOT） tachycardia; 2.Verapamil can prevent right ventricular outflow tract （RVOT） tachycardia, the mechanism may be because that verapamil can improve the remodeling of L-type calcium channel α1c subunit in right ventricular outflow tract myocardium.3.L-type calcium channel have been found to play an important role in the generation and sustainment of RVOT-VT.