title: Mechanisms of propagation of intercellular calcium waves in arterial smooth muscle cells.
abstract: In rat mesenteric arteries, smooth muscle cells exhibit intercellular calcium waves in response to local phenylephrine stimulation. These waves have a velocity of approximately 20 cells/s and a range of approximately 80 cells. We analyze these waves in a theoretical model of a population of coupled smooth muscle cells, based on the hypothesis that the wave results from cell membrane depolarization propagation. We study the underlying mechanisms and highlight the importance of voltage-operated channels, calcium-induced calcium release, and chloride channels. Our model is in agreement with experimental observations, and we demonstrate that calcium waves presenting a velocity of approximately 20 cells/s can be mediated by electrical coupling. The wave velocity is limited by the time needed for calcium influx through voltage-operated calcium channels and the subsequent calcium-induced calcium release, and not by the speed of the depolarization spreading. The waves are partially regenerated, but have a spatial limit in propagation. Moreover, the model predicts that a refractory period of calcium signaling may significantly affect the wave appearance.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory of Cell Biophysics, Lausanne, Switzerland.
authors.forename: Michèle
authors.initials: M
authors.lastname: Koenigsberger
authors.forename: Dominique
authors.initials: D
authors.lastname: Seppey
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Bény
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Meister
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D018118:Chloride Channels / Q000378:metabolism; D004553:Electric Conductivity; D005110:Extracellular Space / Q000378:metabolism*; D015640:Ion Channel Gating; D008638:Mesenteric Arteries / Q000166:cytology*; D008954:Models, Biological; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D051381:Rats
chemical_list: D018118:Chloride Channels; D002118:Calcium