Direct action of an angiotensin II receptor blocker on angiotensin II-induced left atrial conduction delay in spontaneously hypertensive rats
Direct action of an angiotensin II receptor blocker on angiotensin II-induced left atrial conduction delay in spontaneously hypertensive rats
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DOI：
10.1038/hr.2009.89
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发表时间：
2009-08-01
影响因子：
5.4
通讯作者：
Takeyama, Youici
中科院分区：
文献类型：
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作者：
Matsuyama, Narihisa;Tsutsumi, Takeshi;Takeyama, Youici
在这项研究中，血管紧张素II（Ang II）受体阻滞剂（ARB）的抑制作用对Ang II诱导的传导阻滞在左心房进行了研究。记录自发性高血压大鼠（SHR（Izm）s）左心房小梁的跨膜动作电位和有效不应期（ERP）。记录前，SHR（Izm）s已接受或未接受奥美沙坦酯（AT 1受体阻断剂，3.0 mg kg（-1））治疗8周。在快速电刺激（RES）过程中，在灌注Ang II（10（-8）M）或Ang II + ARB（10（-7）M）的情况下，研究激动时间（AT）和传导阻滞频率的变化。采用组织学切片定量评估左心房间质纤维化。虽然当以基本周期长度驱动制备物时，两组之间的动作电位参数和ERP没有差异，但在RES期间观察到Ang II诱导的传导延迟，并且在ARB治疗的SHRIzms中这被显著抑制（P
In this study, the inhibitory action of angiotensin II (Ang II) receptor blocker (ARB) on Ang II-induced conduction blocking in the left atrium was studied. Transmembrane action potentials and effective refractory period (ERP) were recorded from the left atrial trabeculae of spontaneously hypertensive rats (SHR(Izm)s) that had been treated with or without olmesartan medoxomil (AT1 receptor blocker, 3.0 mg kg(-1)) for 8 weeks before the recording. During rapid electrical stimulation (RES), changes in activation time (AT) and frequencies of the conduction block were studied under perfusion of Ang II (10(-8) M) or Ang II plus ARB (10(-7) M). Interstitial fibrosis in the left atrium was quantitatively assessed using histological sections. Although action potential parameters and ERP did not differ between the two groups when preparations were driven with a basic cycle length, an Ang II-induced conduction delay was observed during RES, and this was significantly suppressed in SHRIzms treated with ARB (P