Cell volume control in phospholemman (PLM) knockout mice: Do cardiac myocytes demonstrate a regulatory volume decrease and is this influenced by deletion of PLM?

Abstract

In addition to modulatory actions on Na+-K+-ATPase, phospholemman (PLM) has been proposed to play a role in cell volume regulation. Overexpression of PLM induces ionic conductances, with 'PLM channels' exhibiting selectivity for taurine. Osmotic challenge of host cells overexpressing PLM increases taurine efflux and augments the cellular regulatory volume decrease (RVD) response, though a link between PLM and cell volume regulation has not been studied in the heart. We recently reported a depressed cardiac contractile function in PLM knockout mice in vivo, which was exacerbated in crystalloid-perfused isolated hearts, indicating that these hearts were osmotically challenged. To address this,..