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Diadenosine tetraphosphate‐induced inhibition of ATP‐sensitive K + channels in patches excised from ventricular myocytes
Author(s) -
Jovanovic Aleksandar,
Terzic Andre
Publication year - 1996
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1996.tb15180.x
Subject(s) - intracellular , myocyte , biophysics , patch clamp , chemistry , biology , biochemistry , microbiology and biotechnology , receptor
Diadenosine 5′,5′‐P 1 , P 4 ‐tetraphosphate (A P4 A) has been termed ‘alarmone’ due to its role in intracellular signaling during metabolic stress. It is not known whether A p4 A could modulate ATP‐sensitive K + (K ATP ) channels, a family of channels regulated by the metabolic status of a cell. We applied the single‐channel patch‐clamp technique to measure the effect of A p4 A on K ATP channels. When applied to the intracellular side of patches, excised from guinea‐pig ventricular myocytes, A p4 A inhibited K ATP channel activity, in a reversible and concentration‐dependent (half‐maximal concentration ∼ 17 μ m ) manner. We conclude that A p4 A, a naturally occurring diadenosine polyphosphate, is actually an inhibitor of the myocardial K ATP channel.