[Regulation of cell function by level of hydration].

The hydration state of mammalian cells is dynamic and changes within minutes under the influence of nutrients, hormones and oxidative stress. Such changes in cell hydration act as an independent signal which modulates cellular metabolism and gene expression by activating intracellular signalling systems. Although the structures which sense hydration changes are unknown, this creates a novel and elegant mechanism for adaptation of cell function and gene expression to environmental challenges and provides new aspects for clinical medicine.