Bezold-Jarisch reflex blunts arterial Baroreflex via the shift of neural arc toward lower sympathetic nerve activity
Bezold-Jarisch reflex blunts arterial Baroreflex via the shift of neural arc toward lower sympathetic nerve activity
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DOI：
10.2170/jjphysiol.54.395
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发表时间：
2004-08-01
期刊：
影响因子：
--
通讯作者：
Sunagawa, K
中科院分区：
文献类型：
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作者：
Kashihara, K;Kawada, T;Sunagawa, K
虽然Bezold-Jorich（BJ）反射是潜在的诱发急性心肌缺血或梗死，其对动脉压力感受性反射的静态特性的影响仍有待分析的神经和外周弧之间的平衡图。神经弧代表压力感受器压力输入和传出交感神经活动（SNA）之间的静态输入-输出关系，而外周弧代表SNA和动脉压（AP）之间的静态输入-输出关系。在8只麻醉家兔中，我们将颈动脉窦压力从40 mmHg逐步增加到160 mmHg，每隔1分钟增加20 mmHg，同时在对照条件下和静脉注射苯双胍（PBG，100 μ g）激活BJ反射期间测量肾SNA和AP。kg（-l.）min（-1））。神经弧近似为S形曲线，而外周弧近似为直线。PBG使工作点的AP从91.3 ± 2.4降至71.7 ± 3.1 mmHg（P < 0.01），并使工作点的总环路增益从-1.31 ± 0.44降至-0.51 ± 0.14（P < 0.05）。平衡图表明，PBG引起的神经弧向低SNA的平行移动，使最大SNA降低到约60%的控制。PBG降低神经和外周弧增益约43%和77%，分别在工作点。总之，BJ反射通过神经弧向更低SNA的移位来钝化动脉压力感受性反射。
Although the Bezold-Jarisch (BJ) reflex is potentially evoked during acute myocardial ischemia or infarction, its effects on the static characteristics of the arterial baroreflex remain to be analyzed in terms of an equilibrium diagram between the neural and peripheral arcs. The neural arc represents the static input-output relationship between baroreceptor pressure input and efferent sympathetic nerve activity (SNA), whereas the peripheral arc represents that between SNA and arterial pressure (AP). In 8 anesthetized rabbits, we increased carotid sinus pressure stepwise from 40 to 160 mmHg in increments of 20 mmHg at one-minute intervals while measuring renal SNA and AP under control conditions and during the activation of the BJ reflex by intravenous administration of phenylbiguanide (PBG, 100 mug(.)kg(-l.)min(-1)). The neural arc approximated a sigmoid curve whereas the peripheral arc approximated a straight line. PBG decreased AP at the operating point from 91.3 +/- 2.4 to 71.7 +/- 3.1 mmHg (P < 0.01), and attenuated the total loop gain at the operating point from -1.31 +/- 0.44 to -0.51 +/- 0.14 (P < 0.05). The equilibrium diagram indicated that PBG caused a parallel shift of the neural arc toward lower SNA such that the maximum SNA was reduced to approximately 60% of control. PBG decreased neural and peripheral arc gains at the operating point to approximately 43% and 77%, respectively. In conclusion, the BJ reflex blunts arterial baroreflex via the shift of the neural arc toward lower SNA.