Abstract
1. Rat, rabbit and guinea-pig liver slices were incubated in media at 37 degrees C to study effects of ouabain and of metabolic inhibition on tissue composition.2. Slices initially incubated in oxygenated balanced medium did not swell when exposed to either balanced media or potassium-free media containing ouabain in concentrations ranging from 0.1 to 10 mM though they lost potassium and gained a comparable amount of sodium.3. Without prior incubation in oxygenated medium slices initially swelled when incubated with ouabain but then maintained their new volume.4. Slices whose metabolism was inhibited by incubation with nitrogen and 1 or 10 mM iodoacetamide lost as much potassium as slices exposed to 10 mM ouabain but became swollen with the uptake of sodium, chloride and water.5. The results show that liver cells, like renal cortical cells, possess a metabolically dependent, ouabain-insensitive, potassium-independent mechanism concerned in the regulation of cellular volume.