Inositol Trisphosphate Mobilizes Intracellular Calcium in Permeabilized Adrenal Chromaffin Cells |
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| Authors: | Sally J Stoehr James E Smolen Ronald W Holz Bernard W Agranoff† |
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| Institution: | Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, U.S.A.;Department of Pharmacology, University of Michigan, Ann Arbor, Michigan, U.S.A.;Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, U.S.A. |
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| 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. |
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| Keywords: | Inositol trisphosphate Intracellular calcium Chromaffin cells Quin 2 |
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