Tetrodotoxin-sensitive sodium channels in normal human fibroblasts and normal human glia-like cells.

Abstract

Tetrodotoxin-sensitive Na channels are detectable in normal human fibroblasts and in glia-like cells at appreciable levels when compared to that in established neuronal cell lines in culture. The 2- to 3-fold stimulations of Na influx are seen in the presence of 0.2 mM veratridine and scorpion [Leiurus quinguestriatus] venom at 0.1 mg/ml. Tetrodotoxin (2 .mu.M) inhibits the observed stimulation of Na influx. These neurotoxins may act on the voltage-sensitive Na ionophore of excitable cells, and the presence of such channels in cells generally considered nonexcitable raises questions regarding both the uniqueness of the ionophore as a property of excitable cells and the origin of the cells generally described as fibroblasts.