Renin Depletion in the Dog 1

Abstract

The administration of DOCA and salt is known to deplete renin stores in the rat; however, the authors are unable to find any published regimen which depletes renal renin stores in the dog. We are presenting renal vein renin assays demonstrating the efficacy of DOCA and salt in canine renin depletion.

Methods. Four dogs weighing between 13 and 25 kg were used in this study. Three received 12.5 mg of DOCA intramuscularly and 6 g of sodium chloride by mouth daily for 14 days. The fourth dog was not pre-treated with DOCA and salt and served as a control. Each dog was stimulated to release renin as follows:

Under pentobarbital anesthesia (25 mg/kg) a lower midline incision was made and a snare was passed about the abdominal aorta above the renal arteries. A catheter was placed in a radial artery to measure systemic arterial pressure above the snare and a similar catheter was placed in a femoral artery to measure arterial pressure below the snare. After blood pressure stabilized, a control blood sample was obtained from the left renal vein. Renal arterial pressure was then reduced to one half of the systemic pressure by constricting the aortic snare. The amount of aortic constriction was increased during the ensuring time to maintain renal arterial pressure relatively constant at one half of the systemic pressure. Twenty and 40 min after renal artery constriction, blood samples were again obtained from the left renal vein. Renal vein renin activity was determined by Laragh's modification of Pickens incubation technique and the Boucher bioassay (1,2).