Ivabradine does not acutely affect open-loop baroreflex static characteristics and spares sympathetic heart rate control in rats
Ivabradine does not acutely affect open-loop baroreflex static characteristics and spares sympathetic heart rate control in rats
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DOI：
10.1016/j.ijcard.2017.11.115
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发表时间：
2018-04-15
影响因子：
3.5
通讯作者：
Sugimachi, Masaru
中科院分区：
文献类型：
--
作者：
Yamamoto, Hiromi;Kawada, Toru;Sugimachi, Masaru
目的：为了评估静脉内伊伐布雷定，选择性心动过缓剂，对颈动脉窦压力反射介导的交感动脉压（AP）和心率（HR）responses.Methods和结果的急性影响：在麻醉和迷走神经切断的Wistar-Kyoto大鼠（n = 6），颈动脉窦压力感受器区域被隔离。在静脉注射伊伐布雷定（2 mg/kg）之前和之后，检查了内脏交感神经活动（SNA）、AP和HR对逐步压力输入的反应变化。伊伐布雷定不影响SNA（91.8 +/- 6.5 vs. 93.5 +/- 9.8%）或AP（89.6 +/- 10.6 vs. 91.0 +/- 9.7 mm Hg）的反应范围。伊伐布雷定使最小HR从369.4 +/- 8.4显著降低至223.3 +/- 13.2（P < 0.001），但未减弱HR反应范围（69.1 +/- 7.0 vs. 82.5 +/- 9.6 beats/min）。伊伐布雷定不会严重影响压力反射介导的交感神经AP调节，尽管存在显著心动过缓，但也不会影响交感神经HR反应的幅度。保留的交感HR反应（β受体阻滞剂无法提供）可能有助于伊伐布雷定的一些有益临床作用。(C)2017爱思唯尔B. V.保留所有权利。
Aims: To assess the acute effects of intravenous ivabradine, a selective bradycardic agent, on carotid sinus baroreflex-mediated sympathetic arterial pressure (AP) and heart rate (HR) responses.Methods and results: In anesthetized and vagotomized Wistar-Kyoto rats (n = 6), carotid sinus baroreceptor regions were isolated. Changes in splanchnic sympathetic nerve activity (SNA), AP, and HR in response to a step-wise pressure input were examined before and after intravenous ivabradine (2 mg/kg). Ivabradine did not affect the response range of SNA (91.8 +/- 6.5 vs. 93.5 +/- 9.8%) or AP (89.6 +/- 10.6 vs. 91.0 +/- 9.7 mm Hg). Ivabradine significantly reduced the minimum HR from 369.4 +/- 8.4 to 223.3 +/- 13.2 (P < 0.001) but did not attenuate the HR response range (69.1 +/- 7.0 vs. 82.5 +/- 9.6 beats/min).Conclusions: Ivabradine does not acutely affect baroreflex-mediated sympathetic AP regulation and also spares the magnitude of the sympathetic HR response, despite significant bradycardia. The preserved sympathetic HR response, which could not be afforded by beta-blockers, may contribute to some beneficial clinical effects of ivabradine. (C) 2017 Elsevier B.V. All rights reserved.