Volume Regulation in Cultured Cells

Abstract

This chapter discusses the basic issues involved in studies of cell volume regulation in cells from vertebrates, focusing on unattached cells, such as erythrocytes, lymphocytes, and Ehrlich ascites tumor cells. These cells are especially well suited for studies of cell volume regulation, because the relevant parameters (cell volume, cell water, ion and amino acid contents, fluxes of tracer ions, and others) can be measured far more simply and accurately than in attached cells. These symmetrical cells are particularly useful as possible model systems for investigating the ionic mechanisms of transporters found in certain epithelia. The chapter highlights classification of the ion transport mechanisms involved in volume regulation. Among the volume-regulatory mechanisms proposed are bumetanide- and furosemide-sensitive cotransport, amiloride-sensitive Na + /H + exchange, pimozide-sensitive changes in K + and Cl – conductance, and K + /H + exchange. Many of these transporters are similar to those observed in more complex systems, such as epithelia. The chapter presents a summary of the mechanisms shown to be involved in regulatory volume increase and regulatory volume decrease in different cell types.