Mibefradil, A T-type calcium channel antagonist in Y1 cells.
The effect of mibefradil, a new nondihydropyridine Ca2+ channel antagonist, was investigated on Y1 cells which exhibited T-and L-type Ca2+ currents. In the great majority of these cells, mibefradil rapidly and selectively blocked T-type Ca2+ current in a dose-dependent manner with a half maximum action at 10-7 M. Furthermore, the specific L-type Ca2+ channel inhibitor, nifedipine, blocked the Ca2+ inward current remaining after the action of mibefradil. Mibefradil does not modify the voltage-dependent characteristics of the current/voltage relationship. However, mibefradil is more effective at depolarized membrane potential.
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Department of Physiology and Biophysics, Faculty of Medicine, University of Sherbrooke, Quebec, Canada.
Gallo-Payet
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Payet
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D000310:Adrenal Gland Neoplasms / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects* / Q000502:physiology; D020746:Calcium Channels, L-Type; D020747:Calcium Channels, T-Type; D004305:Dose-Response Relationship, Drug; D004553:Electric Conductivity; D020748:Mibefradil; D051379:Mice; D009543:Nifedipine / Q000494:pharmacology; D009994:Osmolar Concentration; D013764:Tetrahydronaphthalenes / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D001562:Benzimidazoles; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D020747:Calcium Channels, T-Type; D013764:Tetrahydronaphthalenes; D020748:Mibefradil; D009543:Nifedipine