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Cytosolic free Ca2+ in insulin secreting cells and its regulation by isolated organelles |
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Published in | Experientia. 1984, vol. 40, no. 10, p. 1052-60 | |
Abstract | The role of Ca2+ in secretagogue-induced insulin release is documented not only by the measurements of 45Ca fluxes in pancreatic islets, but also, by direct monitoring of cytosolic free Ca2+, [Ca2+]i. As demonstrated, using the fluorescent indicator quin 2, glyceraldehyde, carbamylcholine and alanine raise [Ca2+]i in the insulin secreting cell line RINm5F, whereas glucose has a similar effect in pancreatic islet cells. The regulation of cellular Ca2+ homeostasis by organelles from a rat insulinoma, was investigated with a Ca2+ selective electrode. The results suggest that both the endoplasmic reticulum and the mitochondria participate in this regulation, albeit at different Ca2+ concentrations. By contrast, the secretory granules do not appear to be involved in the short-term regulation of [Ca2+]i. Evidence is presented that inositol 1,4,5-trisphosphate, which is shown to mobilize Ca2+ from the endoplasmic reticulum, is acting as an intracellular mediator in the stimulation of insulin release. | |
Keywords | Adenine Nucleotides/metabolism — Alanine/pharmacology — Animals — Biological Transport, Active — Calcimycin/pharmacology — Calcium/physiology — Cytosol/metabolism — Ethers/pharmacology — Glucose/pharmacology — Glyceraldehyde/pharmacology — Humans — Inositol 1,4,5-Trisphosphate — Inositol Phosphates/physiology — Insulin/secretion — Ionomycin — Islets of Langerhans/cytology — Membrane Potentials/drug effects — Models, Biological — Organoids/physiology — Verapamil/pharmacology | |
Identifiers | DOI: 10.1007/bf01971451 PMID: 6436050 | |
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Citation (ISO format) | PRENTKI, M, WOLLHEIM, Claes. Cytosolic free Ca2+ in insulin secreting cells and its regulation by isolated organelles. In: Experientia, 1984, vol. 40, n° 10, p. 1052-60. https://archive-ouverte.unige.ch/unige:55476 |