title: Modulation of potassium channels via the α1B-adrenergic receptor in human osteoblasts.
abstract: Recent studies have demonstrated the involvement of the sympathetic nerve system in bone metabolism. We have previously demonstrated the expression of adrenergic receptors in the human osteoblast SaM-1 cell line. The aim of this study was to reveal the function of these receptors in osteoblasts using electrophysiological methods. During whole-cell patch clamp recording, the application of noradrenaline reduced the currents induced by a voltage ramp, and the effect was larger in the positive potential range. Pretreatment with the selective α(1B)-adrenergic receptor antagonist chloroethylclonidine eliminated the inhibitory effect of noradrenaline. Using Cs-based pipette solution to block potassium channels, the inhibitory effect of noradrenaline disappeared. In contrast, the effect was unaffected in the presence of tetraethylammonium (TEA), a potassium channel blocker. These results suggest that noradrenaline suppresses Cs-sensitive and TEA-insensitive potassium channels via the α(1B)-adrenergic receptor in human osteoblasts.
authors.affiliation: Department of Pharmacology, School of Dentistry, Aichi-Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kodama
authors.forename: Akifumi
authors.initials: A
authors.lastname: Togari
mesh_terms: D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D002460:Cell Line; D003000:Clonidine / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D008297:Male; D008564:Membrane Potentials / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism / Q000502:physiology; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques / Q000379:methods; D026902:Potassium Channel Blockers / Q000494:pharmacology; D015221:Potassium Channels / Q000378:metabolism*; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology*; D055815:Young Adult
chemical_list: D000317:Adrenergic alpha-Antagonists; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D018340:Receptors, Adrenergic, alpha-1; C051731:chlorethylclonidine; D003000:Clonidine; D009638:Norepinephrine