title: Two stable cell lines for screening of calcium channel blockers.
abstract: Stable cell lines are potentially excellent tools for large-scale screening of new compounds. Two carboxyterminal-deleted constructs of the two splice variants a and b of the calcium channel class C alpha 1 subunit were expressed stably in HEK 293 cells. Each cell line produced regular L-type calcium currents. The opening and closing of the calcium channel elicited by potassium depolarization was followed by Fura-2 transients. These transients were blocked by the calcium channel blocker mibefradil with a concentration for 50% inhibition of 1.7 microM. The cell lines expressing the truncated cardiac alpha 1C-a or smooth muscle alpha 1C-b calcium channel were both blocked by nisoldipine under patch clamp conditions. Nisoldipine interacted with higher affinity with the alpha 1C-b channel than with the alpha 1C-a channel. These results indicate that the two cell lines retain the differential dihydropyridine sensitivity of smooth muscle and cardiac calcium channels and may be potential tools for the screening of L-type calcium channel blockers.
authors.affiliation: Institut für Pharmakologie und Toxikologie der TU München, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Seisenberger
authors.forename: A
authors.initials: A
authors.lastname: Welling
authors.forename: A
authors.initials: A
authors.lastname: Schuster
authors.forename: F
authors.initials: F
authors.lastname: Hofmann
mesh_terms: D001562:Benzimidazoles / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002460:Cell Line; D004095:Dihydropyridines / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D016257:Fura-2 / Q000737:chemistry; D006321:Heart / Q000187:drug effects; D020748:Mibefradil; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D015737:Nisoldipine / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D016133:Polymerase Chain Reaction; D011188:Potassium / Q000378:metabolism; D013329:Structure-Activity Relationship; D013764:Tetrahydronaphthalenes / Q000494:pharmacology; D014162:Transfection
chemical_list: D001562:Benzimidazoles; D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D013764:Tetrahydronaphthalenes; D020748:Mibefradil; D015737:Nisoldipine; C038806:1,4-dihydropyridine; D011188:Potassium; D016257:Fura-2