Peri-ureteric collateral vessels in rabbits with experimental renal hypertension

The development of collaterals to an ischemic kidney was studied in rabbits with two-kidney Goldblatt hypertension. Hypertension was produced by applying a silver clip of 0.9 mm in internal diameter on the left renal artery with the right kidney intact. Peri-ureteric collaterals were found at autopsy in 27 (32.9%) of 82 animals that were killed 7 days (early stage) and in 30 (40.5%) of 74 animals that were killed in more than 70 days (late stage) after clipping. The average blood pressure was 123.8 +/- 2.6 (SE) mmHg in animals with collaterals vs. 125.3 +/- 2.1 mmHg in animals without them in the early stage, and 142.5 +/- 4.4 mm Hg in animals with collaterals vs. 122.6 +/- 3.3 mmHg in animals without them in the late stage. These results indicate that the collaterals to an ischemic kidney develop independently of the rises in blood pressure during the first week and the presence of collaterals is associated with moderate to severe hypertension in the late stage.