Diadenosine-hexaphosphate is an inhibitory ligand of myocardial ATP-sensitive K+ channels.
P1P6-di(adenosine-5')hexaphosphate (Ap6A) has been recently demonstrated in mammalian cells, yet its function remains unknown. Using single-channel current recordings, we studied the effect of Ap6A on guinea-pig cardiac ATP-sensitive K+ (K(ATP) channels. When applied to the intracellular side of excised membrane patches, Ap6A produced a concentration-dependent inhibition (half-maximal inhibitory concentration: 14 microM; Hill coefficient: 1.1) of K(ATP) channel activity. We conclude that Ap6A is a potent inhibitory ligand of K(ATP) channels.
Jovanović
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Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA.
Terzic
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D000818:Animals; D002478:Cells, Cultured; D015226:Dinucleoside Phosphates / Q000494:pharmacology*; D006168:Guinea Pigs; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000502:physiology
D015226:Dinucleoside Phosphates; D026902:Potassium Channel Blockers; D015221:Potassium Channels; C070070:diadenosine 5',5''''-P1,P6-hexaphosphate