人动脉平滑肌钙激活钾通道与遗传因素的关系探讨(英文)

ASSOCIATION OF Ca ^(2+) ACTIVATED K+ CHANNEL IN HUMAN ARTERIES WITH GENETIC FACTOR

目的 探讨高血压病 (Essentialhypertension ,EH)患者及正常血压者肠系膜动脉平滑肌钙激活钾通道 (Ca2 + activatedK+ channel ,Kca)的功能活动及其与遗传因素的相关性。方法 用膜片钳单通道记录技术记录胞内和胞外Ca2 + 对无EH家族史的正常血压者 (Nn 组 )、有EH家族史的正常血压者 (Nf 组 )、无EH家族史的EH患者 (En 组 )、有EH家族史的EH患者 (Ef 组 )肠系膜动脉平滑肌 (Mesentericarterialsmoothmus cle ,MASM)细胞的Kca开放概率 (Po)、平均开放时间 (To)、平均关闭时间 (Tc)及电流幅值 (Am)的影响。结果 内面向外式膜片下 ,Nf 组、Ef 组MASM细胞Kca的Po、To、Tc 与Nn 组和En 组比较 ,无显著性差异 ;细胞贴附式膜片下 ,当胞外Ca2 + 浓度≥ 1.8× 10 -3 mmol/L时 ,Nf 组和Ef 组的MASM细胞Kca的Po 分别低于Nn 组 ,En组 ,To 缩短和Tc 延长。结论 人MASM细胞Kca对胞内Ca2 + 的敏感性与遗传因素无关 ;人MASM细胞Kca对胞外Ca2 + 的敏感性降低与遗传因素有关 ,Kca对胞外Ca2 + 的敏感性降低可能是EH的发生机制之一。

Objective:To investigate the association of Ca 2+ activated K+ channel(K ca)in the mesenteric artery smooth muscle cells of essential hypertensive and normotensive with genetic factor.Methods:The standard patch clamp technique was used to record the single Kca channel current in inside-out and cell-attached patch clamp.Results:In inside-out patch, there was no significant difference in P o, T o, T c of K ca in EH with familial history(E f) and EH without familial history (E n); the same results were found in normotensive without familial history (N n) and normotensive with familial history(N s).In cell-attached patch, the extracellular Ca 2+concentration was≥1.8×10 -3 mmol/L, P o were significantly lower in E s and N f groups than in the control individually, with T o decreasing and Tc increasing.Conclusions:The sensitivity of K ca to intracellular Ca 2+ was not associated with genetic factor. The decreased sensitivity to extracellular Ca 2+ of K ca was associated with genetic factor, which may play a role in the pathogenesis of EH.