Inositol Trisphosphate Mobilizes Intracellular Calcium in Permeabilized Adrenal Chromaffin Cells

Using permeabilized chromaffin cells and the fluorescent probe Quin 2 (an indicator of free Ca 2+ ), we found that inositol trisphosphate (IP 3 ) specifically triggered an immediate and dose-dependent release of Ca 2+ from intracellular stores. Desensitization of the response was observed at nonsaturating concentrations of inositol trisphosphate and resequestration of Ca 2+ was not observed. While representing only a small fraction of the total cellular Ca 2+ , the amount released by IP 3 could significantly raise cytosolic Ca 2+ and may account for muscarinic effects on Ca 2+ metabolism in chromaffin cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65306/1/j.1471-4159.1986.tb13014.x.pd