Intracellular Potassium and Steroidogenesis of Isolated Rat Adrenal Cells: Effect of Potassium Ions and Angiotensin II on Purified Zona Glomerulosa Cells
A method involving centrifugation through phthalate ester oils is described for the rapid separation of isolated cells from suspending medium. Intracellular K concentrations and intracellular water space values for isolated adrenal zona glomerulosa and zona fasciculata cells are given. The effects of angiotensin II and a high external K concentration (8.4 mmol/l) on intracellular K contents, intracellular water spaces and hence intracellular K concentrations of purified glomerulosa cells were investigated. Corticosterone secretion was also measured. Previously reported results showing a significant increase in K content with high external K were confirmed. Angiotensin II slightly, but significantly, decreased K content. No significant change in intracellular water space or intracellular K concentration was observed with either stimulus. Both stimuli significantly increased corticosterone production. There was no correlation between the percentage increase in K content or concentration and the percentage increase in steroid output after stimulation with high external K. Angiotensin II does not stimulate steroidogenesis in adrenal glomerulosa cells by raising the intracellular K concentration. The small, but statistically insignificant, increase caused by high-K medium is unlikely to be causally linked to steroidogenesis.