Molecular differential expression of voltage-gated sodium channel α and β subunit mRNAs in five different mammalian cell lines.

Voltage-gated sodium channels are composed of one α subunit and one or more auxiliary β subunits. A standard reverse transcription-polymerase chain reaction assay was used to detect the mRNAs encoding for seven α subunits (Nav1.1, Nav1.2, Nav1.3, Nav1.4, Nav1.5, Nav1.6, Nav1.9) and for the two non-covalently linked β1 and β3 auxiliary subunits in five different cell lines from rat, mouse and human origin. A semi-quantitavive RT-PCR analysis allowed to evaluate in each cell line, the relative expression level of each NaCh subunit previously detected. The expression profile of the cell lines was compared with that obtained from rat and mouse neural, skeletal muscle and cardiac tissues. This data provide a standard for the study of the modulation of the sodium channel expression in mammalian excitable tissues.