To obtain high levels of glutathione in isolated hepatocytes an isolation procedure shorter than 16 min was used. This procedure gave a moderately high yield of viable cells (200--300 X 10(6) cells/10 g liver) with 44 +/- 3 nmol of glutathione/10(6) cells. Incubation in Krebs-Henseleit solution containing 2% albumin resulted in a continuous loss of reduced glutathione from the cells, while incubation in a medium containing amino acids and horse serum resulted in increased levels, suggesting active synthesis for 5 h. A short and apparently harmless depletion of reduced glutathione was induced by diethylmaleate or cumene hydroperoxide. A depletion of reduced glutathione lasting more than 1 h was accompanied by an increased cellular leakage. The depletion was induced by either diethylmaleate plus paracetamol or diethylmaleate alone in higher concentrations. A common mechanism for these toxic responses is suggested.