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Inhibition of Na + ‐dependent Ca 2+ efflux from heart mitochondria by amiloride analogues
Author(s) -
Jurkowitz Marianne S.,
Altschuld Ruth A.,
Brierley Gerald P.,
Cragoe Edward J.
Publication year - 1983
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(83)80768-6
Subject(s) - amiloride , mitochondrion , chemistry , efflux , biophysics , sodium , biochemistry , biology , organic chemistry
The Na + ‐induced release of accumulated Ca 2+ from heart mitochondria is inhibited by amiloride, benzamil and several other amiloride analogues. These drugs do not affect uptake or release of Ca 2+ mediated by the ruthenium red‐sensitive uniporter and their effects, like those of diltiazem and other Ca 2+ ‐antagonists, appear to be localized principally at the Na + /Ca 2+ antiporter of the mitochondrion. Benzamil inhibits Na + /Ca 2+ antiport non‐competitively with respect to [Na + ] with a K i of 167 μM. In the presence of 1.5 mM P i the K i for benzamil inhibition of this reaction is decreased to 87 μM.