A technique is described in which the circulation of the adrenal glands of the dog is completely isolated on the arterial side as well as on the venous side. With this technique the adrenal glands can be perfused in situ and, if desired, in vivo without any interruption of their blood supply and without any direct trauma. The adrenal glands may be perfused with the dog's own blood pumped by the dog's own heart (autoperfusion), or with the blood of another dog pumped by a mechanical pump. It was found that unless both recipient and donor dogs are hypophysectomized, the adrenal glands of the recipient dog are maximally stimulated and are not responsive to large doses of ACTH. If hypophysectomized animals are used, the perfused adrenals secrete small amounts of hydrocortisone and are responsive to very small doses of ACTH. This technique would seem to be an ideal means of studying the direct effect of any agent on the adrenal glands without the interference of other endocrine glands or other organs.

In the anesthetized dog the pCO2 of the urine, arterial blood, and renal venous blood was measured before and after the intravenous administration of Diamox (acetazoleamide). The pCO2 of the urine always rose to a much greater degree than did the pCO2 of the arterial or renal venous blood This rise in urinary pCO2 could be explained satisfactorily neither by a rise in intracellular pCO2 nor by an increase in the rate of urine flow, but seemed best explained by the fact that Diamox itself acted as a urinary buffer.