AN EXPERIMENTAL-MODEL FOR THE MEASUREMENT OF RENAL-FUNCTION AFTER TEMPORARY URETERAL OBSTRUCTION IN THE RAT

We present the results obtained with a ureterovesical implant after ip silateral ureteral obstruction in the rat, suitable for the study of r enal function after deobstruction in these animals. Thirty-seven male Wistar rats weighing 260 to 300 g were submitted to distal right urete ral ligation and divided into 3 groups, A (N = 13, 1 week of obstructi on), B (N = 14, 2 weeks of obstruction) and C (N = 10, 3 weeks of obst ruction). The animals were then submitted to ureterovesical implantati on on the right side and nephrectomy on the left side. During the 4-we ek follow-up period serum levels of urea and creatinine were measured on the 2nd, 7th, 14th, 21st and 28th day and compared with preoperativ e levels. The ureterovesical implantation included a psoas hitch proce dure and the ureter was pulled into the bladder using a transvesical s uture. During the first week of the postoperative period 8 animals die d, 4/13 in group A (1 week of obstruction) and 4/14 in group B (2 week s of obstruction), When compared to preoperative serum levels, urea an d creatinine showed a significant increase (P<0.05) on the 2nd postope rative day in groups A and B, with a gradual return to lower levels. H owever, the values in group B animals were higher than those in group A at the end of the fellow-up. In group C, 2/10 animals (after 3 weeks of obstruction) were sacrificed at the time of ureterovesical implant ation due to infection of the obstructed kidneys. The remaining animal s in this group were operated upon but all of them died during the fir st week of follow-up due to renal failure. This technique of ureterove sical implantation in the rat provides effective drainage of the upper urinary tract, permitting the development of an experimental model fo r the study of long-term renal function after a period of ureteral obs truction.