Invited review: arteriolar smooth muscle mechanotransduction: Ca(2+) signaling pathways underlying myogenic reactivity.
The smooth muscle of arterioles responds to an increase in intraluminal pressure with vasoconstriction and with 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 Ca(2+). However, it is becoming clear that considerable complexity exists in the spatiotemporal characteristics of the Ca(2+) signal and that changes in intracellular Ca(2+) may play roles other than direct effects on the contractile process via activation of myosin light-chain phosphorylation. The involvement of Ca(2+) may extend to modulation of ion channels and release of Ca(2+) from the sarcoplasmic reticulum, alterations in Ca(2+) sensitivity, and coupling between cells within the vessel wall. The purpose of this brief review is to summarize the current literature relating to Ca(2+) and the arteriolar myogenic response. Consideration is given to coupling of Ca(2+) changes to the mechanical stimuli, sources of Ca(2+), involvement of ion channels, and spatiotemporal aspects of intracellular Ca(2+) signaling.
Hill
M A
MA
Microvascular Biology Group, School of Medical Sciences, RMIT University, Bundoora, Victoria 3083, Australia. Michael.Hill@rmit.edu.au
Zou
H
H
Potocnik
S J
SJ
Meininger
G A
GA
Davis
M J
MJ
D000818:Animals; D001160:Arterioles / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology*; D006801:Humans; D007473:Ion Channels / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D012519:Sarcoplasmic Reticulum / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D014661:Vasoconstriction / Q000502:physiology; D014664:Vasodilation / Q000502:physiology
D007473:Ion Channels