title: Voltage dependent calcium channel expression in isolated osteoclasts.
abstract: In this study the expression of voltage-dependent calcium channels on osteoclast plasma membrane has been investigated. We found that osteoclasts were sensitive to KCl-induced depolarization. In this circumstance a 4 fold transient cytosolic calcium concentration ([Ca2+]i) increase was observed. This increase was dose-dependent. Its half maximal effect was achieved at 30 mM KCl. Voltage sensitive calcium channels in osteoclasts were inhibited by specific antagonists. Nicardipine, a dihydropyridine derivative, was the most effective, inducing complete block of the channels at 10(-6) M. Verapamil (phenylalkylamine) and diltiazem (benzodiazepine) were less effective. These results are consistent with the presence, on the osteoclast membrane, of L-type voltage-sensitive calcium channels.
authors.forename: A
authors.initials: A
authors.lastname: Teti
authors.forename: M
authors.initials: M
authors.lastname: Grano
authors.forename: S
authors.initials: S
authors.lastname: Colucci
authors.forename: L
authors.initials: L
authors.lastname: Argentino
authors.forename: R
authors.initials: R
authors.lastname: Barattolo
authors.forename: A
authors.initials: A
authors.lastname: Miyauchi
authors.forename: S L
authors.initials: SL
authors.lastname: Teitelbaum
authors.forename: K A
authors.initials: KA
authors.lastname: Hruska
authors.forename: A
authors.initials: A
authors.lastname: Zambonin Zallone
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D002645:Chickens; D004110:Diltiazem / Q000494:pharmacology; D004594:Electrophysiology; D005260:Female; D009529:Nicardipine / Q000494:pharmacology; D010010:Osteoclasts / Q000187:drug effects / Q000502:physiology*; D011189:Potassium Chloride / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
chemical_list: D015220:Calcium Channels; D011189:Potassium Chloride; D014700:Verapamil; D009529:Nicardipine; D004110:Diltiazem