The block of the expressed L-type calcium channel is modulated by the beta 3 subunit.
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.
Lacinová
L
L
Institut für Pharmakologie and Toxikologie TU München, Germany.
Ludwig
A
A
Bosse
E
E
Flockerzi
V
V
Hofmann
F
F
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*
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