Human cardiac sodium channels expressed in Xenopus oocytes.
We report the expression of voltage-dependent Na+ channels in Xenopus oocytes injected with total RNA isolated from explanted human hearts. The expressed channels demonstrate characteristic voltage-dependent gating, inhibition by tetrodotoxin, and selectivity for Na+. Oocytes injected with sterile water or intentionally degraded RNA had no similar channel activity. The antiarrhythmic agent lidocaine (20 microM) inhibits current flow through the channel in a voltage-dependent fashion. Na+ channels expressed by injection of human cardiac RNA into Xenopus oocytes qualitatively resemble channels in the native tissue.
Tomaselli
G F
GF
Department of Medicine, Howard Hughes Medical Institute, Johns Hopkins School of Medicine, Baltimore, Maryland 21205.
Feldman
A M
AM
Yellen
G
G
Marban
E
E
D000818:Animals; D004594:Electrophysiology; D015870:Gene Expression; D006706:Homeostasis; D006801:Humans; D007267:Injections; D008012:Lidocaine / Q000494:pharmacology; D009206:Myocardium / Q000032:analysis / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism*; D012313:RNA / Q000494:pharmacology; D012146:Rest; D012964:Sodium / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D014982:Xenopus laevis / Q000378:metabolism*
D015222:Sodium Channels; D012313:RNA; D008012:Lidocaine; D012964:Sodium