Intravascular pressure regulates local and global Ca2+ signaling in cerebral artery smooth muscle cells

Author:

Jaggar Jonathan H.1

Affiliation:

1. Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163

Abstract

The regulation of intracellular Ca2+ signals in smooth muscle cells and arterial diameter by intravascular pressure was investigated in rat cerebral arteries (∼150 μm) using a laser scanning confocal microscope and the fluorescent Ca2+ indicator fluo 3. Elevation of pressure from 10 to 60 mmHg increased Ca2+spark frequency 2.6-fold, Ca2+ wave frequency 1.9-fold, and global intracellular Ca2+ concentration ([Ca2+]i) 1.4-fold in smooth muscle cells, and constricted arteries. Ryanodine (10 μM), an inhibitor of ryanodine-sensitive Ca2+ release channels, or thapsigargin (100 nM), an inhibitor of the sarcoplasmic reticulum Ca2+-ATPase, abolished sparks and waves, elevated global [Ca2+]i, and constricted pressurized (60 mmHg) arteries. Diltiazem (25 μM), a voltage-dependent Ca2+ channel (VDCC) blocker, significantly reduced sparks, waves, and global [Ca2+]i, and dilated pressurized (60 mmHg) arteries. Steady membrane depolarization elevated Ca2+ signaling similar to pressure and increased transient Ca2+-sensitive K+ channel current frequency e-fold for ∼7 mV, and these effects were prevented by VDCC blockers. Data are consistent with the hypothesis that pressure induces a steady membrane depolarization that activates VDCCs, leading to an elevation of spark frequency, wave frequency, and global [Ca2+]i. In addition, pressure induces contraction via an elevation of global [Ca2+]i, whereas the net effect of sparks and waves, which do not significantly contribute to global [Ca2+]i in arteries pressurized to between 10 and 60 mmHg, is to oppose contraction.

Publisher

American Physiological Society

Subject

Cell Biology,Physiology

Cited by 113 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

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