Voltage‐activated Ca2+ currents in insulin‐secreting cells

FEBS Letters

Dunne, Mark J.¹  Findlay, Ian¹ 

[1] MRC Secretory Control Research Group, The Physiological Laboratory, University of Liverpool, PO Box 147, Liverpool L69 3 BX, England

关键词: RINm5F cell;    Whole-cell patch clamp;    Ca2+ current;    Spike potential;   

DOI  :  10.1016/0014-5793(85)81040-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Membrane voltage and voltage-clamped membrane currents have been investigated with the whole-cell patch clamp method in the insulin-secreting cell line RINm5F. The mean resting membrane potential of RINm5F cells was found to be −52 mV. Overshooting spike potentials could be evoked by membrane depolarisation in the absence of a secretagogue. Inward membrane currents evoked by depolarising voltage steps were dependent upon extracellular Ca²⁺ and blocked by Co²⁺, nifedipine and verapamil. Outward membrane currents which were evoked by depolarising voltage steps to positive membrane potentials were reduced when Ca²⁺ entry was prevented. It is concluded that the voltage-activated Ca²⁺ currents underlie the voltage-activated spike potentials recorded from insulin-secreting cells.

【 授权许可】

Unknown