title: Caffeine-induced Ca(2+) oscillations in type I horizontal cell of carp retina: a mathematical model.
abstract: Oscillations in intracellular free Ca(2+) concentration ([Ca(2+)]i) have been observed in a variety of cell types. In the present study, we constructed a mathematical model to simulate the caffeine-induced [Ca(2+)]i oscillations based on experimental data obtained from isolated type I horizontal cell of carp retina. The results of model analysis confirm the notion that the caffeine-induced [Ca(2+)]i oscillations involve a number of cytoplasmic and endoplasmic Ca(2+) processes that interact with each other. Using this model, we evaluated the importance of store-operated channel (SOC) in caffeine-induced [Ca(2+)]i oscillations. The model suggests that store-operated Ca(2+) entry (SOCE) is elicited upon depletion of the endoplasmic reticulum (ER). When the SOC conductance is set to 0, caffeine-induced [Ca(2+)]i oscillations are abolished, which agrees with the experimental observation that [Ca(2+)]i oscillations were abolished when SOC was blocked pharmacologically, verifying that SOC is necessary for sustained [Ca(2+)]i oscillations.
authors.affiliation: a School of Biomedical Engineering ; Shanghai Jiao Tong University ; Shanghai , China.
authors.forename: Ting
authors.initials: T
authors.lastname: Lv
authors.forename: Pu-Ming
authors.initials: PM
authors.lastname: Zhang
authors.forename: Hai-Qing
authors.initials: HQ
authors.lastname: Gong
authors.forename: Pei-Ji
authors.initials: PJ
authors.lastname: Liang
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D020013:Calcium Signaling; D002347:Carps; D008959:Models, Neurological; D051248:Retinal Horizontal Cells / Q000187:drug effects / Q000378:metabolism*
chemical_list: D002110:Caffeine
keywords: 2-APB, 2-Aminoethoxydiphenyl borate; ANOVA, Analysis of variance; CICR, Ca2+-induced Ca2+ release; Ca2+ oscillations; ER, Endoplasmic reticulum; H1 HC, Type I horizontal cell; HC, Horizontal cell; L-VGCC, Ca2+channel; NCX, Na+/Ca2+ exchanger; PM, Plasma membrane; PMCA, Plasma membrane Ca2+-ATPase; RyR, Ryanodine receptor; SERCA, Sarco/endoplasmic reticulum Ca2+-ATPase; SNK, Student-Newman-Keuls; SOC, Store-operated channel; SOCE, Store-operated Ca2+ entry; STIM, Stromal interaction molecule; TRP, Transient receptor potential; [Ca2+]ER, Free Ca2+ concentration inside the lumen of the ER; [Ca2+]i, Intracellular free Ca2+ concentration; caffeine; computational model; retinal horizontal cell; ryanodine receptor; store-operated channel