Loss of functional voltage-gated sodium channels in persistent mumps virus-infected PC12 cells.
Rat pheochromocytoma (PC12) cells, persistently infected with mumps virus (MV), failed to generate full-sized stimulus-evoked action potentials (SEAPs) when examined by intracellular electrophysiological recording techniques. Application of tetrodotoxin (TTX) had little or no effect on MV-reduced SEAPs, indicating that the number of functional voltage-gated Na+ channels was decreased or their operation was blocked by the virus. In contrast, MV-infected cells generated normal Ca2+ spikes when bathed in a solution containing TTX, tetraethylammonium ions and a high concentration (20 mM) of Ca2+. In addition, when infected cells bathed in TTX were superfused with Co2+ the SEAP profile reverted to that typical of PC12 cells with functional voltagegated K+ channels only. These observations indicate that MV affects voltage-gated Na+ channels, but spares voltage-gated Ca2+ and K+ channels of persistently infected cells.
Stauffer
E K
EK
Department of Physiology, School of Medicine, University of Minnesota-Duluth 55812-2487.
Ziegler
R J
RJ
D000310:Adrenal Gland Neoplasms / Q000150:complications / Q000503:physiopathology; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D005071:Evoked Potentials / Q000187:drug effects; D009107:Mumps / Q000503:physiopathology*; D010673:Pheochromocytoma / Q000150:complications / Q000503:physiopathology; D051381:Rats; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D015220:Calcium Channels; D015222:Sodium Channels; D013779:Tetrodotoxin