Effect of Adrenal Steroids on Renal Tubular Reabsorption of Bicarbonate

Abstract

Administration of desoxy-corticosterone-acetate (DCA) to dogs on a moderate or high dietary intake of NaCl leads to increased renal tubular reabsorption of bicarbonate. Cortisone and adrenocorticotropic hormone are much less effective. This increased reabsorption of bicarbonate is believed to be due to K depletion since it was prevented by oral administration of KC1, occurred only in animals with initially low plasma K, and could be abolished by dietary Na restriction which prevents K loss. Dietary K depletion can lead to an increment in bicarbonate reabsorption similar to that produced by DCA administration. Animals with increased renal reabsorption of bicarbonate, when exposed to acute respiratory acidosis, reabsorb significantly more bicarbonate than untreated animals at similar levels of pCO2. Bicarbonate reabsorption reaches values comparable to those seen in chronic respiratory acidosis.