Prisca Mbikou (Avtor), Aleš Fajmut (Avtor), Milan Brumen (Avtor), Etienne Roux (Avtor)

Povzetek

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.

Ključne besede

biofizika;matematično modeliranje;modeliranje;kalcijeve oscilacije;gladke mišice;krčenje mišic;miozin kinaza;razvoj sile;matematični modeli;ne zaključna dela;biophysics;mathematical modelling;modelling;calcium oscillations;contractions;force development;muscle cells;smooth muscles;myosin kinase;

Podatki

Jezik: Angleški jezik
Leto izida:
Tipologija: 1.01 - Izvirni znanstveni članek
Organizacija: UM PEF - Pedagoška fakulteta
UDK: 577.353
COBISS: 15168776 Povezava se bo odprla v novem oknu
ISSN: 1085-9195
Št. ogledov: 1863
Št. prenosov: 95
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Slovenski jezik
Sekundarne ključne besede: Biofizika;
URN: URN:SI:UM:
Vrsta dela (COBISS): Članek v reviji
Strani: str. 233-251
Letnik: ǂVol. ǂ46
Zvezek: ǂno. ǂ3
Čas izdaje: 2006
ID: 8724209