title: The block of the expressed L-type calcium channel is modulated by the beta 3 subunit.
abstract: The alpha 1C subunit of the L-type calcium channel was stable, expressed alone or in combination with the beta 3 subunit in Chinese hamster ovary cells. The beta 3 subunit enhanced significantly the inactivation of barium currents indicating that both subunits interacted with each other. The beta 3 subunit decreased significantly the half-maximal inhibitory concentration of the calcium channel blockers (-)-gallopamil and verapamil, but did not affect significantly the block caused by isradipine and mibefradil at the holding potentials of -80 mV and -40 mV. These results suggest that the beta 3 subunit affects distinctly the interaction of the expressed alpha 1C subunit with different classes of organic calcium channel blockers.
authors.affiliation: Institut für Pharmakologie and Toxikologie TU München, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Lacinová
authors.forename: A
authors.initials: A
authors.lastname: Ludwig
authors.forename: E
authors.initials: E
authors.lastname: Bosse
authors.forename: V
authors.initials: V
authors.lastname: Flockerzi
authors.forename: F
authors.initials: F
authors.lastname: Hofmann
mesh_terms: D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology; D016466:CHO Cells; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000096:biosynthesis / Q000187:drug effects / Q000502:physiology*; D020746:Calcium Channels, L-Type; D006224:Cricetinae; D005246:Feedback; D005711:Gallopamil / Q000494:pharmacology*; D015870:Gene Expression; D007425:Intracellular Membranes / Q000378:metabolism; D017275:Isradipine / Q000494:pharmacology; D046911:Macromolecular Substances; D008564:Membrane Potentials / Q000187:drug effects; D020748:Mibefradil; D008861:Microsomes / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D011817:Rabbits; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000378:metabolism; D013329:Structure-Activity Relationship; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D014162:Transfection; D014700:Verapamil / Q000494:pharmacology*
chemical_list: D001562:Benzimidazoles; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D013764:Tetrahydronaphthalenes; D020748:Mibefradil; D005711:Gallopamil; D014700:Verapamil; D017275:Isradipine