Invited Review: Arteriolar smooth muscle mechanotransduction: Ca2+ signaling
pathways underlying myogenic reactivity.
Hill, Michael A., Hui Zou, Simon J. Potocnik, and Gerald A. Meininger, and Michael J.
Davis.
1Microvascular Biology Group, School of Medical Sciences, RMIT University,
Bundoora, Victoria 3083, Australia; 2Department of Physiology, University of
Massachusetts Medical School, Worcester, Massachusetts 01655; and 3Department of
Medical Physiology, College of Medicine, Texas A&M University, College Station,
Texas 77843
APStracts 8:0264A, 2001.
The smooth muscle of arterioles responds to an increase in intraluminal pressure with
vasoconstriction and vasodilation when pressure is decreased. Such myogenic
vasoconstriction provides a level of basal tone that enables arterioles to appropriately
adjust diameter in response to neurohumoral stimuli. Key in this process of
mechanotransduction is the role of changes in intracellular Ca2+. However, it is
becoming clear that considerable complexity exists in the spatiotemporal characteristics
of the Ca2+ signal and that changes in intracellular Ca2+ may play roles other than direct
effects on the contractile process via activation of myosin light-chain phosphorylation.
The involvement of Ca2+ may extend to modulation of ion channels and release of Ca2+
from the sarcoplasmic reticulum, alterations in Ca2+ sensitivity, and coupling between
cells within the vessel wall. The purpose of this brief review is to summarize the current
literature relating to Ca2+ and the arteriolar myogenic response. Consideration is given to
coupling of Ca2+ changes to the mechanical stimuli, sources of Ca2+, involvement of ion
channels, and spatiotemporal aspects of intracellular Ca2+ signaling.
APS Manuscript Number A388-1.
Article publication pending J Appl Physiol
ISSN 1080-4757 Copyright 2001 The American Physiological Society.
Published in APStracts on 18 June 2001