Experimental studies on the carbonic anhydrase activity. IX. The mode of action of adrenocortical steroids, especially aldosterone, on the carbonic anhydrase in mice and rats.

In the present experiments we investigated the effects of adrenalectomy and aldosterone, DOCA and hydrocortisone replacement on carbonic anhydrase activity in various organs of rats and mice. At the same time we reviewed all the experimental results hitherto obtained, and discussed the mechanism of action of aldosterone on the kidney. The characteristic feature of the action of aldosterone on renal carbonic anhydrase activity of normal or adrenalectomized mice and rats is that the effects in these two animal species are contrary to each other, being accelerative in the former species and inhibitory in the latter, whereas the effect of adrenalectomy on the renal enzymic activity is inhibitory in the former species and accelerative in the latter. This is an example of a difference in hormonal action between animal species. To explain the results the following hypothesis is offered: Presumably there is a species difference in the synthesis of renal carbonic anhydrase after aldosterone treatment. This difference may be dependent on the amount of other synthesized enzymes participating in Na metabolism, for example, ATPase. That is, in mice the increase in carbonic anhydrase synthesis affected by aldosterone may cause the decrease in ATPase synthesis. The situation is reversed in rats.