Cell Volume Maintenance and Regulation in Eukaryotes: Overview and Perspectives

Abstract

This chapter provides an overview of cell volume maintenance and regulation in eukaryotes. Cells are essential in the maintenance of a proper architecture of the macromolecular supports to which many interacting components are bound. Considering cell volume control in eukaryotes, there are two completely different types of processes; both processes avoid osmotic gradients and therefore, the net movement of water between the cells and their surrounding fluid. In the first type of process, the intracellular fluid is actively kept close to isosmotic equilibrium with the extracellular one. The other mechanism implicates the control of the osmolality of the extracellular fluid, whatever the osmolality, or the availability of water in the external medium. In a large variety of animals, the inorganic ions, Na + and Cl - , are the prominent blood osmotic effectors and the control of blood osmolality is essentially concerned with the adjustment of their concentrations. The relative importance as well as the nature of the major osmotic effectors, used in cell volume regulation, varies with the species considered.