title: Inositol trisphosphate mobilizes intracellular calcium in permeabilized adrenal chromaffin cells.
abstract: Using permeabilized chromaffin cells and the fluorescent probe Quin 2 (an indicator of free Ca2+), we found that inositol trisphosphate (IP3) specifically triggered an immediate and dose-dependent release of Ca2+ from intracellular stores. Desensitization of the response was observed at nonsaturating concentrations of inositol trisphosphate and resequestration of Ca2+ was not observed. While representing only a small fraction of the total cellular Ca2+, the amount released by IP3 could significantly raise cytosolic Ca2+ and may account for muscarinic effects on Ca2+ metabolism in chromaffin cells.
mesh_terms: D000313:Adrenal Medulla / Q000166:cytology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D002463:Cell Membrane Permeability; D002837:Chromaffin Granules / Q000378:metabolism*; D002838:Chromaffin System / Q000378:metabolism*; D004072:Digitonin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000494:pharmacology*; D013403:Sugar Phosphates / Q000494:pharmacology*
chemical_list: D007295:Inositol Phosphates; D013403:Sugar Phosphates; D015544:Inositol 1,4,5-Trisphosphate; D004072:Digitonin; D002118:Calcium