TY - JOUR
T1 - A model of calcium regulation in smooth muscle cell
AU - Wong, A. Y.K.
AU - Klassen, G. A.
PY - 1993/3
Y1 - 1993/3
N2 - A model of smooth muscle cell is proposed to describe the mechanisms by which intracellular calcium (Cai) is regulated when the cell is stimulated by noradrenaline (NA)/agonist (Ag) or depolarized. The intracellular Ca2+ store is comprised of two calcium pools: A-store which is sensitive to inositol 1,4,5 trisphosphate (IP3) and C-store, insensitive to IP3 but sensitive to Cai. The A-store is refilled by Ca2+ from C-store and reuptake of Cai. The uptake rate is dependent on the degree of filling in the A-store. The C-store, activated by Cai, is replenished by extracellular Ca2+ (Ca0). IP3 generated by NA or Ag changes the A-store permeability, discharging its Ca2+ into the cytosol. Depolarization activates Ca2+ current through the L-type channels. The following events are simulated and compared with experimental observations: (a) Cai transient stimulated by high K+; (b) Cai transient and Ca2+ efflux induced by shortlasting and longlasting NA in the absence of Ca0; (c) effect of lanthanum on NA-induced Cai and Ca2+ efflux; and (d) effects of nifedipine, ryanodine, BAY K 8644 and cyclopiazonic acid on Cai.
AB - A model of smooth muscle cell is proposed to describe the mechanisms by which intracellular calcium (Cai) is regulated when the cell is stimulated by noradrenaline (NA)/agonist (Ag) or depolarized. The intracellular Ca2+ store is comprised of two calcium pools: A-store which is sensitive to inositol 1,4,5 trisphosphate (IP3) and C-store, insensitive to IP3 but sensitive to Cai. The A-store is refilled by Ca2+ from C-store and reuptake of Cai. The uptake rate is dependent on the degree of filling in the A-store. The C-store, activated by Cai, is replenished by extracellular Ca2+ (Ca0). IP3 generated by NA or Ag changes the A-store permeability, discharging its Ca2+ into the cytosol. Depolarization activates Ca2+ current through the L-type channels. The following events are simulated and compared with experimental observations: (a) Cai transient stimulated by high K+; (b) Cai transient and Ca2+ efflux induced by shortlasting and longlasting NA in the absence of Ca0; (c) effect of lanthanum on NA-induced Cai and Ca2+ efflux; and (d) effects of nifedipine, ryanodine, BAY K 8644 and cyclopiazonic acid on Cai.
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U2 - 10.1016/0143-4160(93)90070-M
DO - 10.1016/0143-4160(93)90070-M
M3 - Article
C2 - 8388778
AN - SCOPUS:0027417969
SN - 0143-4160
VL - 14
SP - 227
EP - 243
JO - Cell Calcium
JF - Cell Calcium
IS - 3
ER -