Intracellular ADP activates K+ channels that are inhibited by ATP in an insulin‐secreting cell line

FEBS Letters

Petersen, Ole H.¹  Dunne, Mark J.¹ 

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

关键词: (RINm5F cell) Patch-clamp K+ channel ADP ATP;    ATP;    adenosine 5′-triphosphate;    ADP;    adenosine 5′-diphosphate;    ADP-β-S;    adenosine 5′-O-(2-thiodiphosphate);    AMP;    adenosine 5′-monophosphate;    cylic AMP;    adenosine 3′:5′-cyclic monophosphate;   

DOI  :  10.1016/0014-5793(86)81532-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

the effect of ADP on ATP-sensitive K⁺ channels in the insulin-secreting RINm5F cell line has been investigated with the help of single-channel current recording from saponin-permeabilized cells. ADP (100–500 μM) markedly activates K⁺ channels when added to the bath solution in contact with the membrane inside. ADP-β-S cannot mimick this effect. During sustained ATP (500 μM)-evoked inhibition of K⁺ channel opening, 500 μM ADP markedly and reversibly activates the channels. Conversely ATP markedly reduces the opening probability of ADP-activated channels. It is suggested that the physiological control of K⁺ channel opening in the insulin-secreting cells is mediated by changes in ATP/ADP ratio rather than being solely determined by the ATP concentration.

【 授权许可】

Unknown