Effects of Ca2+ and a phorbol ester on insulin secretion from islets of langerhans permeabilised by high‐voltage discharge

FEBS Letters

Stutchfield, Jane¹  Howell, Simon L.¹  Jones, Peter M.¹ 

[1] Department of Physiology and MRC Secretory Mechanisms Group, Kings College (KQC), University of London, Campden Hill Road, Kensington, London W8 7 AH, England

关键词: Islets of Langerhans;    High-voltage discharge;    Cytosolic Ca2+;    Exocytosis;    Phorbol ester;   

DOI  :  10.1016/0014-5793(85)81002-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Isolated rat islets of Langerhans permeabilised by high-voltage discharge secreted insulin in response to elevations in Ca²⁺ over the range 100 nM to 10 μM Ca²⁺. The phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA), had no effects on insulin secretion in the absence of Ca²⁺. In the presence of Ca²⁺ concentrations of > 10 nM, TPA produced dose-related shifts in the Ca²⁺-activation curve to lower Ca²⁺ concentrations, together with marked increases in the maximum secretory response to Ca²⁺. These results suggest that, in islets, the activation of protein kinase C is important in modulating both the sensitivity of the exocytotic mechanism to intracellular Ca²⁺, and the magnitude of the insulin secretory response.

【 授权许可】

Unknown