Experiments and mechanochemical modeling of smooth muscle contraction: Significance of filament overlap.
2012 (English)In: Journal of Theoretical Biology, ISSN 0022-5193, E-ISSN 1095-8541, Vol. 297, 176-186 p.Article in journal (Refereed) Published
The main function of smooth muscle is to maintain/regulate the size of different hollow organs through contraction and relaxation. The magnitude of the active force during contraction is dependent on the number of attached cross-bridges, which can be linked to the overlap between the thin and thick filaments. The relevance of filament overlap and the active cross-bridges in smooth muscle is investigated through a mechanical model founded on Hill's three-element model. The mechanical model describes a sarcomere-equivalent contractile unit supported by structural observations with a distinct filament overlap and a realistic framework for the filament sliding behavior based on force-velocity experiments. The mechanical model is coupled to the four-state latch-model by Hai and Murphy to capture the electromechanical activation from intracellular calcium concentration to load-bearing cross-bridges. The model is fitted to isometric experiments performed on the pig carotid media and on isotonic quick-release experiments found in the literature. The proposed coupled mechanochemical model with the description of the filament overlap, which has a significant influence on the results, is able to predict isometric experimental data performed at different muscle lengths. The relevance of the filament overlap and the load-bearing cross-bridges is investigated through the model by simulating additional scenarios that has been documented in the literature.
Place, publisher, year, edition, pages
2012. Vol. 297, 176-186 p.
Smooth muscle, Muscle contraction, Contractile unit, Filament overlap, Modeling
IdentifiersURN: urn:nbn:se:kth:diva-66749DOI: 10.1016/j.jtbi.2011.11.012ISI: 000300652000017PubMedID: 22108241ScopusID: 2-s2.0-84856736341OAI: oai:DiVA.org:kth-66749DiVA: diva2:484610
QC 201201272012-01-272012-01-272012-04-02Bibliographically approved