Effects of aldosterone, actinomycin D, puromycin and cycloheximide on RNA synthesis, carbonic anhydrase and atpase activities of the kidney and on urinary excretion of sodium in adrenalectomized mice

Abstract

Aldosterone (2 μg/kg) administered to adrenalectomized mice increased the synthesis of RNA from [6- 14C]-orotic acid in the kidney and increased the carbonic anhydrase activity but not the microsomal ATPase activity. However, urinary excretion of sodium was decreased 2–4 h after aldosterone administration. Aldosterone increased the specific radioactivity of RNA, but not the overall content of RNA in the kidney. The increase in specific radioactivity is primarily a nuclear RNA. The increase in carbonic anhydrase activity and decrease of urinary excretion of sodium produced by aldosterone were inhibited by actinomycin D (300 μg/kg), puromycin (60 mg/kg) and cycloheximide (1 mg/kg). These findings are consistent with the so called “induction hypothesis”—that is aldosterone would have its major effect in the nucleus, resulting in increased synthesis of RNA and ultimately in increased synthesis of specific enzymes. The results of this study indicate the possibility that kidney carbonic anhydrase may be a mediator of the action of aldosterone on tubular reabsorption of sodium in adrenalectomized mice.