title: Effects of mebudipine and dibudipine, two new calcium channel blockers on voltage-activated calcium currents of PC12 cells.
abstract: Mebudipine and dibudipine are two newly synthesized dihydropyridine (DHP) calcium channel blockers that have been shown to have considerable relaxant effects on vascular and atrial smooth muscle. The in vitro half-lives of mebudipine and dibudipine are reported to be significantly longer than that of nifedipine. In this study, we investigated the effects of mebudipine and dibudipine on voltage-activated Ca2+ channels on differentiated PC12 cells and compared their potencies to amlodipine. Our results point to absence of voltage-activated Ca2+ currents in undifferentiated PC12 cells. It is also concluded that mebudipine and dibudipine, like amlodipine are L-type calcium channel blockers. When tested in a range of 10-100 microM, mebudipine is at least as potent as amlodipine in inhibition of peak Ba2+ currents in differentiated PC12 cells while dibudipine is significantly less potent compared to amlodipine and mebudipine.
authors.affiliation: Razi Institute for Drug Research, Iran University of Medical Sciences, P.O. Box 14155-6183, Tehran, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Rouzrokh
authors.forename: S A
authors.initials: SA
authors.lastname: Ebrahimi
authors.forename: N
authors.initials: N
authors.lastname: Rahbr-Roshandel
authors.forename: M
authors.initials: M
authors.lastname: Mahmoudian
mesh_terms: D017311:Amlodipine / Q000494:pharmacology; D000818:Animals; D017609:Barium Compounds / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D020746:Calcium Channels, L-Type / Q000187:drug effects* / Q000378:metabolism; D002454:Cell Differentiation; D002712:Chlorides / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D008564:Membrane Potentials / Q000187:drug effects; D020932:Nerve Growth Factor / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D016716:PC12 Cells; D051381:Rats
chemical_list: D017609:Barium Compounds; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D002712:Chlorides; C110813:dibudipine; C110812:mebudipine; C024986:barium chloride; D017311:Amlodipine; D020932:Nerve Growth Factor; D009543:Nifedipine