Unbound MEDLINE

Smooth muscle cell calcium activation mechanisms.

Abstract

Smooth muscle cell (SMC) contraction is controlled by the Ca2+ and Rho kinase signalling pathways. While the SMC Rho kinase system seems to be reasonably constant, there is enormous variation with regard to the mechanisms responsible for generating Ca2+ signals. One way of dealing with this diversity is to consider how this system has been adapted to control different SMC functions. Phasic SMCs (vas deferens, uterus and bladder) rely on membrane depolarization to drive Ca2+ influx across the plasma membrane. This depolarization can be induced by neurotransmitters or through the operation of a membrane oscillator. Many tonic SMCs (vascular, airway and corpus cavernosum) are driven by a cytosolic Ca2+ oscillator that generates periodic pulses of Ca2+. A similar oscillator is present in pacemaker cells such as the interstitial cells of Cajal (ICCs) and atypical SMCs that control other tonic SMCs (gastrointestinal, urethra, ureter). The changes in membrane potential induced by these cytosolic oscillators does not drive contraction directly but it functions to couple together individual oscillators to provide the synchronization that is a characteristic feature of many tonic SMCs.

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  • Authors

    Berridge MJ

    Institution

    The Babraham Institute, Babraham, Cambridge CB22 4AT, UK. michael.berridge@bbsrc.ac.uk

    Source

    The Journal of physiology 586:Pt 21 2008 Nov 1 pg 5047-61

    MeSH

    Animals
    Calcium Signaling
    Humans
    Membrane Potentials
    Mice
    Myocytes, Smooth Muscle

    Pub Type(s)

    Journal Article
    Review

    Language

    eng

    PubMed ID

    18787034