title: Ca2+ dynamics in a population of smooth muscle cells: modeling the recruitment and synchronization.
abstract: Many experimental studies have shown that arterial smooth muscle cells respond with cytosolic calcium rises to vasoconstrictor stimulation. A low vasoconstrictor concentration gives rise to asynchronous spikes in the calcium concentration in a few cells (asynchronous flashing). With a greater vasoconstrictor concentration, the number of smooth muscle cells responding in this way increases (recruitment) and calcium oscillations may appear. These oscillations may eventually synchronize and generate arterial contraction and vasomotion. We show that these phenomena of recruitment and synchronization naturally emerge from a model of a population of smooth muscle cells coupled through their gap junctions. The effects of electrical, calcium, and inositol 1,4,5-trisphosphate coupling are studied. A weak calcium coupling is crucial to obtain a synchronization of calcium oscillations and the minimal required calcium permeability is deduced. Moreover, we note that an electrical coupling can generate oscillations, but also has a desynchronizing effect. Inositol 1,4,5-trisphosphate diffusion does not play an important role to achieve synchronization. Our model is validated by published in vitro experiments obtained on rat mesenteric arterial segments.
authors.affiliation: Laboratory of Cell Biophysics, Swiss Federal Institute of Technology, Lausanne, Switzerland. michele.koenigsberger@epfl.ch
authors.forename: Michèle
authors.initials: M
authors.lastname: Koenigsberger
authors.forename: Roger
authors.initials: R
authors.lastname: Sauser
authors.forename: Mathieu
authors.initials: M
authors.lastname: Lamboley
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Bény
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Meister
mesh_terms: D000465:Algorithms; D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D002450:Cell Communication / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008962:Models, Theoretical; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
chemical_list: D014662:Vasoconstrictor Agents; D002118:Calcium