Fig. 1

Cell volume changes (shrinkage and swelling) caused by osmotic perturbation and cell volume regulation thereafter. Osmotic volume decrease (OVD), secretory volume decrease (SVD), and cooling/freezing volume decrease (CVD/FVD) are shortly followed by the regulatory volume increase (RVI), whereas osmotic volume increase (OVI) is by the regulatory volume decrease (RVD). Hormonal volume decrease (HVD) and increase (HVI) are given in parenthesis, because it is not known whether they are followed by RVI and RVD, respectively. The key players for RVI and RVD are cationic HICC channels and anionic VSOR/VRAC channels, respectively. (See text for details.)