动脉粥样硬化兔血管平滑肌大电导钙激活钾通道的活性及其对硝酸甘油反应的探讨

Change of activity of large conductance of calcium- activated potassium channels in vascular smooth muscle from atherosclerotic rabbits and their response to Nitroglycerin

二维码有效期 120s

摘要目的研究动脉粥样硬化(atherosclerosis,AS)时血管平滑肌细胞(vascular smooth muscle cell,VSMC)大电导钙激活钾通道(Large conductance of calcim-activated potassium channnel,BKca)的活性变化及对硝酸甘油(nitroglycerin,NTG)的反应.方法3月龄新西兰兔随机分为实验组(AS组)和对照组(正常组),每组各10只.AS组喂高脂饲料以建立AS模型,对照组喂普通饲料,两组均喂8周.采用单通道膜片钳技术测定VSMC的Bkca的电流及其对NTG的反应.结果随着电压和Ca2+浓度的增加,AS组和对照组的通道开放概率(Po)逐渐增大.AS组的Po较对照组明显增大,P＜0.001.在Ca2+浓度为10-6M下,AS组和对照组的Po增加(68.8620±34.4447)倍和(126.4170±70.6090)倍,P＜0.05.NTG可以显著增加通道的Po,且具有浓度依赖性.在NTG液浓度为10-4M下,AS组和对照组的Po增加(54.7620±23.7193)倍和(108.5950±60.2223)倍,P＜0.05.结论AS组VSMC的BKca活性增强.AS组VSMC的BKca的Ca2+敏感性降低.NTG可激活VSMC的BKca.AS组VSMC的BKca对NTG的反应性下降.