Cells regulate their volume to counteract swelling or shrinkage caused by osmotic challenges and during processes such as cell growth, division, and migration. As water transport across cellular membranes is driven by osmotic gradients, cell volume regulation requires appropriate changes of intracellular concentrations of ions or organic osmolytes such as taurine.
Regulatory volume decrease (RVD) follows the extrusion of intracellular Cl – and K+ and other osmolytes across the plasma membrane. VRAC plays a major role in water transport during volume regulation. Inhibition of VRAC reduces water permeability of the cell membrane of endothelial cells indicating that VRAC might be permeable for water and can be considered as a “wet” channel.