Insulin release independent of a rise in cytosolic free Ca2+ by forskolin and phorbol ester
- 22 April 1985
- journal article
- Published by Wiley in FEBS Letters
- Vol. 183 (2), 433-438
- https://doi.org/10.1016/0014-5793(85)80825-5
Abstract
The role of cytosolic free Ca2+ in insulin release was evaluated using isolated rat pancreatic islets permeabilized with digitonin and incubated in Ca-EGTA buffers to fix free Ca2+ concentration at arbitrary levels. Ca2+ induced insulin release in a concentration-dependent manner with the threshold being between 0.1 and 1 μM. The hormone release was increased by forskolin and 12-O-tetradecanoyl phorbol-13-acetate (TPA), a potent activator of adenylate cyclase and that of protein kinase C, respectively. The findings suggest that activation of both protein kinase A and protein kinase C modulate insulin release without a concomitant increase in cytosolic free Ca2+.Keywords
This publication has 13 references indexed in Scilit:
- Glyceraldehyde, but not cyclic AMP‐stimulated insulin release is preceded by a rise in cytosolic free Ca2+FEBS Letters, 1984
- Dual effects of glucose on the cytosolic Ca2+ activity of mouse pancreatic β‐cellsFEBS Letters, 1984
- Cyclic nucleotides control a system which regulates Ca2+ sensitivity of platelet secretionNature, 1984
- Correlation between cytosolic free Ca2+ and insulin release in an insulin-secreting cell line.Journal of Biological Chemistry, 1984
- Diacylglycerol and phorbol ester stimulate secretion without raising cytoplasmic free calcium in human plateletsNature, 1983
- The phorbol ester TPA increases the affinity of exocytosis for calcium in ‘leaky’ adrenal medullary cellsFEBS Letters, 1983
- Regulation of insulin secretion from islets of Langerhans rendered permeable by electric dischargeBiochemical Journal, 1982
- Regulation of insulin release by calcium.Physiological Reviews, 1981
- The cytoskeleton of digitonin-treated rat hepatocytes.Proceedings of the National Academy of Sciences, 1980
- Metal Chelate Stability Constants of Aminopolycarboxylate LigandsAnalytical Chemistry, 1960