Adrenaline inhibits depolarization‐induced increases in capacitance in the presence of elevated [Ca2+]i in insulin secreting cells

FEBS Letters

Ullrich, Susanne¹  Kampermann, Julia¹  Greger, Rainer¹  Herbst, Martin¹  Lehr, Sabine¹ 

[1] Physiologisches Institut, Albert-Ludwigs Universität Freiburg, Abteilung II, Hermann-Herder-Straße 7, D-79104 Freiburg/Br, Germany

关键词: Insulin secretion;    Adrenaline;    Capacitance measurement;    Patch clamp method;    Intracellular Ca2+ activity;   

DOI  :  10.1016/S0014-5793(97)01081-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cell capacitance (C _m), cell conductance (G _m), access conductance (G _a) and membrane voltage (V _m) were measured simultaneously in insulin secreting cells using the dual frequency method. Depolarization and stimulation of the cells with secretagogues increased C _m. EGTA abolished the increase in [Ca²⁺]_i and prevented the rise of C _m. Adrenaline inhibited the augmentation of C _m without lowering [Ca²⁺]_i. In pertussis toxin pretreated cells adrenaline had no effect. Thus, stimulation of insulin secretion is accompanied by an increase in C _m. Inhibition of exocytosis by adrenaline occurs even in the presence of elevated [Ca²⁺]_i, i.e. at a more distal step of exocytosis.

【 授权许可】

Unknown