Vagal stimulation attenuates sympathetic enhancement of left ventricular function

Author:

Henning R. J.1,Khalil I. R.1,Levy M. N.1

Affiliation:

1. Division of Investigative Medicine, Mt. Sinai Medical Center.

Abstract

We studied the effects of stimulation of the vagal and sympathetic cardiac nerves on left ventricular contraction and relaxation in 16 anesthetized dogs. In each experiment, we paced the ventricles at a fixed rate of 120 beats/min, and we kept the systemic arterial pressure constant. We used the maximum rates of left ventricular pressure rise (dP/dtmax) and fall (dP/dtmin) as our indexes of ventricular contraction and relaxation. Sympathetic nerve stimulation at a frequency of 6 Hz increased dP/dtmax by 802 mmHg/s and raised dP/dtmin by 847 mmHg/s above the control level. The effect of vagal nerve stimulation was directly dependent on the level of sympathetic stimulation. In the absence of sympathetic stimulation, vagal nerve stimulation at a frequency of 5 Hz decreased dP/dtmax by 187 mmHg/s and reduced dP/dtmin by 199 mmHg/s below the control level. When the sympathetic stimulation was 6 Hz, vagal nerve stimulation at 5 Hz decreased dP/dtmax by 513 mmHg/s and reduced dP/dtmin by 709 mmHg/s. Furthermore, propranolol, in doses of 1.5 mg/kg, abolished any significant vagal effect on ventricular contraction or relaxation. We conclude that combined sympathetic-vagal stimulation results in a substantial antagonistic interaction such that vagal stimulation significantly attenuates the sympathetic enhancement of left ventricular function.

Publisher

American Physiological Society

Subject

Physiology (medical),Cardiology and Cardiovascular Medicine,Physiology

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3