The effect of acidosis and alkalosis on in vitro aldosterone production.

There are conflicting data concerning the effect of hydrogen ion concentration (H+) on aldosterone production in vivo. This study examines the effect of changes in H+ on in vitro aldosterone production in isolated adrenal capsular cells of rats. The pH was adjusted to 7.1 or 6.8 using lactic acid and to 7.7 using sodium hydroxide. Potassium and other ions in the incubation medium were maintained at nearly constant levels. There was a significant decrease in aldosterone production when the pH was lowered from 7.4 to 7.1 or to 6.8 and also when the pH was increased to 7.7. This decrease was highly significant when measured in absolute terms or relative to ACTH-stimulated control samples included in each assay. Acidosis and alkalosis both decrease rather than stimulate aldosterone production in vitro and indicate that the observed in vivo stimulation of aldosterone by acidosis most likely is mediated by other aldosterone stimuli. These data also confirm that a marked alkalosis decreases aldosterone production and supports further study of changes in a more physiologic range.