Initial and sustained calcium mobilizations in the parietal cell during stimulations with gastrin, inositol trisphosphate, phorbol ester and exogenous diacylglycerol.
Electron probe X-ray microanalysis revealed that cytoplasmic Ca2+ concentration increased in the restricted apical cytoplasm during stimulation of isolated guinea pig parietal cells with gastrin. Furthermore, this study, using 45Ca2+, aequorin and fura-2, revealed the mechanism involved in intracellular Ca2+ shifts caused by gastrin and the involvements of inositol 1,4,5-trisphosphate (IP3) and diacylglycerol in producing those shifts. The gastrin-mediated and IP3-sensitive Ca2+ pool was located in the smooth-surfaced membrane-enriched areas and released Ca2+ in the initial phase. Gastrin-mediated Ca2+ mobilization was also evoked by diacylglycerol, comprising an intracellular Ca2+ mobilization followed by a late, sustained and more localised Ca2+ entry from the extracellular space.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000331:Aequorin; D000818:Animals; D001572:Benzofurans; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002132:Calcium Radioisotopes; D003593:Cytoplasm / Q000378:metabolism; D004075:Diglycerides / Q000494:pharmacology*; D004533:Egtazic Acid / Q000494:pharmacology; D004577:Electron Probe Microanalysis; D005456:Fluorescent Dyes; D016257:Fura-2; D005755:Gastrins / Q000494:pharmacology*; D005989:Glycerides / Q000494:pharmacology*; D006168:Guinea Pigs; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000494:pharmacology*; D010295:Parietal Cells, Gastric / Q000187:drug effects / Q000378:metabolism*; D013403:Sugar Phosphates / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D001572:Benzofurans; D002132:Calcium Radioisotopes; D004075:Diglycerides; D005456:Fluorescent Dyes; D005755:Gastrins; D005989:Glycerides; D007295:Inositol Phosphates; D013403:Sugar Phosphates; D000001:Calcimycin; D000331:Aequorin; D004533:Egtazic Acid; D015544:Inositol 1,4,5-Trisphosphate; C038237:1-oleoyl-2-acetylglycerol; D000255:Adenosine Triphosphate; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium; D016257:Fura-2