Nonmodal gating of cardiac calcium channels as revealed by dihydropyridines.
نویسندگان
چکیده
منابع مشابه
Nonmodal gating of cardiac calcium channels as revealed by dihydropyridines
The hypothesis that dihydropyridine (DHP)-sensitive calcium channels have three distinct modes of gating has been examined. The major prediction is that the relative frequencies among modes depend on DHP concentration while the kinetics within a mode do not. We tested this by studying whole-cell and single-channel calcium currents in neonatal rat and adult guinea pig cardiac myocytes in differe...
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Dihydropyridines (DHPs) block L-type Ca2+ channels more potently at depolarized membrane potentials, consistent with high affinity binding to the inactivated state. Nisoldipine (a DHP antagonist) blocks the smooth muscle channel more potently than the cardiac one, a phenomenon observed not only in native channels but also in expressed channels. We examined whether this tissue specificity was at...
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We have studied block of L-type calcium channels by intracellular and extracellular application of the ionized dihydropyridine derivatives amlodipine and SDZ 207-180. We find that extracellular application of either drug causes voltage-dependent block of calcium channels. However, neither drug is effective when applied intracellularly. The insensitivity of calcium channels to intracellular drug...
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ژورنال
عنوان ژورنال: Journal of General Physiology
سال: 1989
ISSN: 0022-1295,1540-7748
DOI: 10.1085/jgp.93.6.1243