摘要
目的观察Ang-(1-7)及AngⅡ对犬心房肌细胞外向钾通道电流的作用,揭示其参与房性心律失常的细胞电生理机制。方法急性分离单个犬心房肌细胞,采用全细胞膜片钳方法记录细胞膜快速延迟整流钾电流(Ikr)、缓慢延迟整流钾电流(Iks)、超快速延迟整流钾电流(Ikur)及短暂外向钾电流(Ito)。结果1μmol/LAng-(1-7)可抑制Ikr、Iks,增加Ito,对Ikur无明显影响;0.5μmol/LAngⅡ可增加Ikr、Iks,抑制Ito,对Ikur无明显影响。结论AngⅡ可能通过对外向钾电流的影响促进心房颤动的心房电重构,Ang-(1-7)作为AngⅡ内源性拮抗剂,可拮抗AngⅡ的电生理作用。
Objective To observe the effects of Ang-（1-7） and Ang 1I on outward potassium channel currents in canine atrial myocytes and study the mechanisms of Ang-（1-7） and Ang Ⅱ on atrial arrhythmia. Methods Single canine atrial myocyte was isolated and whole-cell configuration of the patch-clamp technique was used to detect Ikr, Ik,, Ikur and ito. Restilts Ang-（1-7） （1μmol/L） could respectively inhibit Ikr and Iks. Meanwhile Ang-（1-7） increased I,o and had no effect on Ikur. Ang 1/ （0.5μmol/L） could respectively increase Ikr and Ik,. Meanwhile Ang Ⅱ inhibited Ito, and had no effect on Ikur. Conclusion Angiotensin Ⅱ may promote atrial electrical remodeling of atrial fibrillation by effecting on outward potassium currents. As endogenous antagonism of Angiotensin Ⅱ , Angiotensin-（1-7） can antagonize the electrophysiological effects of Angiotensin Ⅱ.
出处
《中国心脏起搏与心电生理杂志》
2007年第1期63-66,共4页
Chinese Journal of Cardiac Pacing and Electrophysiology
