1. A method involving centrifugation through phthalate ester oils is described for the rapid separation of isolated cells from suspending medium. Intracellular potassium concentrations and intracellular water space values for isolated adrenal zona glomerulosa and zona fasciculata cells are given.
2. The effects of angiotensin II and a high external potassium concentration (8·4 mmol/l) on intracellular potassium contents, intracellular water spaces and hence intracellular potassium concentrations of purified glomerulosa cells have been investigated. Corticosterone secretion was also measured. Previously reported results showing a significant increase in potassium content with high external potassium were confirmed. However, angiotensin II slightly, but significantly, decreased potassium content. No significant change in intracellular water space or intracellular potassium concentration was observed with either stimulus.
3. Both stimuli significantly increased corticosterone production. There was no correlation between the percentage increase in potassium content or concentration and the percentage increase in steroid output after stimulation with high external potassium.
4. It is concluded that angiotensin II does not stimulate steroidogenesis in adrenal glomerulosa cells by raising the intracellular potassium concentration. The small, but statistically insignificant, increase caused by high-potassium medium is unlikely to be causally linked to steroidogenesis.