title: Modeling calcium waves in an anatomically accurate three-dimensional parotid acinar cell.
abstract: We construct a model of calcium waves in a three-dimensional anatomically accurate parotid acinar cell, constructed from experimental data. Gradients of inositol trisphosphate receptor (IPR) density are imposed, with the IPR density being greater closer to the lumen, which has a branched structure, and inositol trisphosphate (IP3) is produced only at the basal membrane. We show (1) that IP3equilibrates so quickly across the cell that it can be assumed to be spatially homogeneous; (2) spatial separation of the sites of IP3action and IP3production does not preclude the formation of stable oscillatory Ca2+waves. However, these waves are not waves in the mathematical sense of a traveling wave with fixed profile. They result instead from a time delay between the Ca2+rise in the apical and basal regions; (3) the ryanodine receptors serve to reinforce the Ca2+wave, but are not necessary for the wave to exist; (4) a spatially independent model is not sufficient to study saliva secretion, although a one-dimensional model might be sufficient. Our results here form the first stages of the construction of a multiscale and multicellular model of saliva secretion in an entire acinus.
authors.affiliation: Department of Mathematics, University of Auckland, New Zealand. Electronic address: j.sneyd@auckland.ac.nz.
authors.forename: James
authors.initials: J
authors.lastname: Sneyd
authors.affiliation: Department of Mathematics, University of Auckland, New Zealand.
authors.forename: Shawn
authors.initials: S
authors.lastname: Means
authors.affiliation: Department of Mathematics, University of Auckland, New Zealand.
authors.forename: Di
authors.initials: D
authors.lastname: Zhu
authors.affiliation: Department of Mathematics, University of Auckland, New Zealand.
authors.forename: John
authors.initials: J
authors.lastname: Rugis
authors.affiliation: Department of Pharmacology and Physiology, University of Rochester Medical Centre, Rochester, USA.
authors.forename: Jong Hak
authors.initials: JH
authors.lastname: Won
authors.affiliation: Department of Pharmacology and Physiology, University of Rochester Medical Centre, Rochester, USA.
authors.forename: David I
authors.initials: DI
authors.lastname: Yule
mesh_terms: D061354:Acinar Cells / Q000166:cytology / Q000378:metabolism*; D000465:Algorithms; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D003198:Computer Simulation; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D017136:Ion Transport; D008954:Models, Biological; D010306:Parotid Gland / Q000033:anatomy & histology / Q000166:cytology / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D012463:Saliva / Q000378:metabolism
chemical_list: D053496:Inositol 1,4,5-Trisphosphate Receptors; D019837:Ryanodine Receptor Calcium Release Channel; D015544:Inositol 1,4,5-Trisphosphate; D002118:Calcium
keywords: Calcium oscillations; Inositol trisphosphate receptor; Multiscale modeling; Ryanodine receptor; Saliva secretion