阻断钠离子通道1.8对心脏神经丛功能的影响

The effects of blocking Nav1.8 channels on the cardiac ganglionated plexi function

目的研究局部阻断钠离子通道1.8(Nav1.8)对心脏神经丛(GP)功能的影响。方法 16条实验用杂种犬随机分为A-803467组(Nav1.8阻断剂,n=8)及对照组(5%二甲亚砜/95%聚乙二醇,n=8)。观测于右前神经丛(ARGP)和右下神经丛(IRGP)局部用药前及用药后10min,高频电刺激ARGP引起的窦性心率(SR)、诱发心房颤动(简称房颤)时电压及房颤时心室率(VR)的变化情况。结果伴随刺激电压增加,A-803467组SR下降趋势明显变缓(P=0.013)。与对照组相比,A-803467组高频电刺激ARGP诱发房颤时所需的电压水平明显增加[(4.6±0.3)V vs(3.0±0.4)V,P=0.01]。与基线时SR相比,A-803467组SR下降最大比例为(24.8%±2.1%),而对照组SR下降最大比例为[(49.7%±5.1%),P<0.001]。用药后,A-803467组高频电刺激ARGP时的VR明显增大(P=0.012)。结论 Nav1.8可以调控GP的功能。

Objective To investigate the effects of blocking Navl. 8 channels on the cardiac ganglionated plexi （GP） function. Methods Sixteen mongrel dogs were randomly enrolled. Nay1.8 channels blocker A-803467 （n= 8） or 5% DMSO/95% polyethylene glycol （n： 8, control） was injected into the anterior right ganglionated plexi （ARGP） and the inferior right ganglionated plexi （IRGP）. High-frequency electrical stimulation（HFS） was applied to ARGP to determine its effects on the sinus rate（SR）, ventricular rate during atrial fibrillation（VR） at baseline and 10 min after drug injection. Voltage-SR response curves were constructed and the slowing of the SR at each voltage level was determined. Results Stimulation of the ARGP with incremental voltage levels induced a progressive slowing of the SR （P= 0. 013）. A-803467 markedly increased the voltage required for ARGP stimulation to induce AF compared to control [（4.6±0.3）V versus （3.0±0.4） V, P= 0.01]. A-803467 decreased the maxi- mal percent change in SR compared to baseline by （24.8± 2.1%）, which was significantly different from control [（49.7%± 5.1%）, P〈0. 001]. A-803467 also increased the VR compared to control （P= O. 012）. Conclusions Nay1.8 channels could regulate ganglionated plexi function. [Chinese Journal of Cardiac Pacing and Electrophysiology, 2016,30 （3） ： 246 - 248]