Insulin release independent of a rise in cytosolic free Ca2+ by forskolin and phorbol ester

FEBS Letters

Niki, Atsushi¹  Tamagawa, Tatsuo¹  Niki, Hatsumi¹ 

[1] Department of Medicine, Aichigakum University, School of Dentistry, 2-11 Sguemori, Chikusa, Nagoya 464, Japan

关键词: Insulin release;    Digitonin;    Ca-EGTA;    Forskolin;    Phorbol ester;    Cytosolic free Ca2+;   

DOI  :  10.1016/0014-5793(85)80825-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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⁺.

【 授权许可】

Unknown