Molecular diversity of voltage-gated sodium channel α and β subunit mRNAs in human tissues

Voltage-gated Na+ channels are composed of one α subunit and one or more auxiliary β subunits. A reverse transcription–polymerase chain reaction assay was used to analyse the expression of the nine known α subunits (Nav1.1–Nav1.9) in 20 different human tissues. The mRNA expression of the currently known β subunits (β1, β2, β3 and β4) was also assessed. The mRNAs of voltage-gated Na+ channel α and β subunits were found in a wide variety of human tissues assayed and were present in neuronal and non-neuronal types of cells. These data suggest that, in addition to its well-established role in skeletal muscle, cardiac cells and neurons, voltage-gated Na+ channels might play important, still undetermined local roles in the regulation of cellular functions. These channels could emerge in the next future as potential, new therapeutic targets in the treatment of visceral diseases.