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  • Theoretical and experimental investigation of calcium-contraction coupling in airway smooth muscle
    Mbikou, Prisca ...
    We investigated theoretically and experimentally the ▫$Ca^{2+}$▫-contraction couplingin rat tracheal smooth muscle. ▫$[Ca^{2+}]_i$▫, isometric contraction and myosin light chain (MLC) phosphorylation ... were measured in response to 1 mM carbachol. Theoretical modeling consisted in coupling a model of ▫$Ca^{2+}-dependent$▫ MLC kinase (MLCK) activation with a four-state model of smooth muscle contractile apparatus. Stimulation resulted in a short-time contraction obtained within 1 min, followed by a long-time contraction up to the maximal force obtained in 30 min. ML-7 and Wortmannin (MLCK inhibitors) abolished the contraction. Chelerythrine (PKC inhibitor) did not change the short-time, but reduced the long-time contraction. ▫$[Ca^{2+}]_i$▫ responses of isolated myocytes recorded during the first 90 s consisted in a fast peak, followed by a plateau phase and, in 28 % of the cells, superimposed ▫$Ca^{2+}$▫ oscillations. MLC phosphorylation was maximal at 5 s and then decreased, whereas isometric contraction followed a Hill-shaped curve. The model properlypredicts the time course of MLC phosphorylation and force of the short-time response. With oscillating ▫$Ca^{2+}$▫ signal, the predicted force does not oscillate. According to the model, the amplitude of the plateau and the frequency of oscillations encode for the amplitude of force, whereas the peak encodes for force velocity. The long-time phase of the contraction, associated with a second increase in MLC phosphorylation, may be explained, at least partially, by MLC phosphatase (MLCP) inhibition, possibly via PKC inhibition.
    Vir: Cell biochemistry and biophysics. - ISSN 1085-9195 (Vol. 46, no. 3, 2006, str. 233-251)
    Vrsta gradiva - članek, sestavni del ; neleposlovje za odrasle
    Leto - 2006
    Jezik - angleški
    COBISS.SI-ID - 15168776

    Povezava(-e):

    http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17272850&itool=iconabstr&query_hl=2&itool=pubmed_docsum
    Digitalna knjižnica Univerze v Mariboru – DKUM

vir: Cell biochemistry and biophysics. - ISSN 1085-9195 (Vol. 46, no. 3, 2006, str. 233-251)

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