Effect of transient hydronephrosis on subsequent compensatory renal growth

Apparent augmentation of renal growth occurs in kidneys made temporarily ischemic, or partially obstructed, before contralateral nephrectomy. The study herein was undertaken to investigate the effect of acute complete ureteral occlusion on a subsequent course of renoprival hypertrophy and hypoplasia. Three groups of animals were established. Animals in Group 1 underwent high ligation of the right ureter. Animals in Groups 2 and 3 underwent exposure and manipulation of the right ureter. Forty-eight hours later, animals in Group 1 underwent deligation and contralateral nephrectomy, animals in Group 2 underwent contralateral nephrectomy, and animals in Group 3 underwent sham operation. Animals were then selected 6 and 17 days after their second operative procedure and decapitated; the right kidneys were removed and underwent analysis with respect to wet and dry weight, total RNA, DNA, and protein content. At 6 days and at 17 days, animals in Groups 1 and 2 demonstrated no difference between these groups, although the remaining kidneys from animals in Group 1 and Group 2 were significantly larger than Group 3 animals. When compared to Group 3 animals, wet renal weight at 17 days had increased by 41 per cent, total bulk RNA had increased by 26 per cent, and total bulk DNA had increased by 33 per cent. The data support the clinical impression that transient, complete ureteral obstruction is well tolerated by the normal kidney, and that the metabolic response to obstruction does not hinder recovery after release of obstruction.