A Study of the Factors Concerned in Renal Hypertension. ∗

Abstract

Since the fundamental work of Goldblatt and his associates, 1 persistent hypertension in dogs by renal ischemia has been produced by other investigators. 2 , 3 , 4 , ⁵, 6 However its etiology and exact mechanism are still unknown.

We have been particularly interested in the effects of clamping one of the renal arteries. Various observers 1 , ⁵, 6 have noted that following the clamping of one renal artery, one of 3 results may be expected; viz., (a) a permanent rise, (b) a temporary rise or (c) no alteration in blood pressure. This report is based on observations in 6 dogs in whom unilateral renal artery clamping by the Goldblatt technique was carried out. Five of these 6 dogs showed a rise in blood pressure following this procedure. In 2 of these 5 dogs, the blood pressure returned to normal within 3 and 8 weeks, respectively; the blood pressure in the other 3 fell somewhat but did not return to the preoperative level. The blood pressures were uniformly determined in the afternoon on trained animals. A direct arterial puncture was made under local anesthesia (2% procain sub-cutaneously) with an ordinary hypodermic needle. The pressure was recorded with a calibrated Hamilton manometer on bromide paper. 7 From 30 to 101 days following the unilateral clamping, the normal kidney was removed from each of the 6 dogs, leaving only the kidney with its renal artery previously clamped. In 5 of the 6 dogs, a marked rise in both systolic and diastolic pressures occurred following the removal of the normal kidney. The sixth dog, which died in uremia and had never shown any rise in blood pressure, was found at necropsy to have had the renal artery completely occluded by the Goldblatt clamp.