Tetrodotoxin-sensitive fast Na+ current in embryonic chicken osteoclasts.
A voltage-dependent, fast, transient inward current was characterized in embryonic chicken osteoclasts using the permeabilized patch configuration of the patch-clamp technique. The current was activated by depolarizations to higher than -28 +/- 4 mV from a holding potential of -80 mV. It peaked within 1-1.5 ms, and inactivated within 3.3-6.9 ms. The 50% inactivation voltage was -59 +/- 6 mV with a steepness factor of 0.11 +/- 0.06. The current disappeared with the removal of extracellular Na+ and was reversibly blocked by tetrodotoxin (K0.5 < 15 nM) but not by verapamil (< or = 100 microM). We conclude that this new current in embryonic chicken osteoclasts is a sodium current known from excitable cells.
D000818:Animals; D002642:Chick Embryo; D003470:Culture Media; D066298:In Vitro Techniques; D010010:Osteoclasts / Q000187:drug effects / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D012964:Sodium / Q000378:metabolism; D015222:Sodium Channels / Q000187:drug effects / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology*; D014700:Verapamil / Q000494:pharmacology
D003470:Culture Media; D015222:Sodium Channels; D013779:Tetrodotoxin; D012964:Sodium; D014700:Verapamil