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Intracellular ADP activates K + channels that are inhibited by ATP in an insulin‐secreting cell line
Author(s) -
Dunne Mark J.,
Petersen Ole H.
Publication year - 1986
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(86)81532-0
Subject(s) - intracellular , biophysics , membrane potential , chemistry , atp–adp translocase , insulin , adenosine triphosphate , membrane , biochemistry , endocrinology , biology , inner mitochondrial membrane
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.