PMID: 7581301Jan 1, 1995Paper

Inositol trisphosphate and cyclic ADP ribose as long range messengers generating local subcellular calcium signals

Journal of Physiology, Paris
O H Petersen

Abstract

The process of messenger-mediated release of Ca2+ from intracellular stores, which is of great importance in virtually all cell types including neurons, can best be studied in cells lacking voltage-gated Ca2+ channels in the plasma membrane. In pancreatic acinar cells agonist-evoked repetitive cytosolic Ca2+ spikes are due to release of Ca2+ via inositoltrisphosphate (IP3) and ryanodine receptors and reuptake into the stores via thapsigargin-sensitive Ca2+ pumps. At low acetylcholine (ACh) or cholecystokinin concentrations the cytosolic Ca2+ spikes are mostly confined to the secretory granule area of the polarized pancreatic acinar cells. Similar results can be obtained by intracellular infusion of IP3 (or one of its non-metabolizable analogues) or cyclic ADP ribose. This suggests that high affinity IP3 and ryanodine receptors are concentrated in the secretory granule area. We have generated an 'artificial synapse' on isolated acinar cells by having a cell-attached patch pipette filled with ACh on the basal membrane. Initially, ACh is prevented from making contact with the receptors by the negative potential applied to the pipette. When the pipette polarity is switched to positive ACh can bind to its receptors. Using digital Ca...Continue Reading

References

Jan 1, 1984·The Journal of Membrane Biology·H StrebI Schulz
Jan 1, 1994·Annual Review of Physiology·O H PetersenH Kasai

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Citations

Jun 12, 1999·Biochemical and Biophysical Research Communications·H TakemuraA Segawa

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