[Na/K pump and intracellular monovalent cations: novel mechanism of excitation-transcription coupling involved in inhibition of apoptosis]

Abstract

The Na/K pump plays a key role in the regulation of the intracellular concentrations of monovalent cations and related cell function leading to electrogenesis and excitation-contraction coupling. We focus this review on the analysis of recent data showing that (i) inhibition of the Na/K pump triggers a signaling cascade independently of modulation of the intracellular [Na+]i/[K+]i ratio; (ii) elevation of [Na+]i under sustained inhibition of the Na/K pump leads to expression of a set of genes by [Ca2+]i-dependent and independent pathways; (iii) [Na+]i-sensitive genes are involved in the inhibition of programmed cell death (apoptosis) in vascular smooth muscle cells.