ABSTRACT
BACKGROUND: Unilateral ureteral obstruction (UUO) is a traditional surgical method that can cause renal interstitial fibrosis in rats in a short period of time (1-2 weeks), but it can develop many postoperative complications and result in a high mortality. OBJECTIVE: To optimize and improve the UUO operation in rats for reducing the incidence of postoperative complications and improving the survival rate of animals, and to detect the pathophysiological indicators of rats modeled by UUO, providing background data for the basic research on functional pharmacology. METHODS: Twenty male Sprague-Dawley rats were randomly divided into four groups, followed by traditional UUO ligation, improved UUO ligation, undissociated ureteral ligation, and opening the abdominal cavity with no ureter ligation (sham group), respectively. At 14 days postoperatively, the successful rate of renal interstitial fibrosis model, mortality rate, and the incidence of postoperative complications were compared between groups. Another 28 Sprague-Dawley rats, half male and half female, were randomly divided into improved UUO group and control group. Physiological indexes, including urine analysis, blood cells analysis, blood biochemical analysis, were tested as background information. Besides, the pathological changes of kidney tissues were compared between groups using hematoxylin-eosin staining and Masson staining at 14 and 21 days postoperatively. RESULTS AND CONCLUSION: Compared with the undissociated ureteral ligation group, the successful rate of modeling was higher in the traditional and improved UUO groups. The improved UUO surgery with double ligation of the middle ureter and no cutting of the middle ureter was characterized by easier operation, smaller surgical wound, faster modeling and higher successful rate of renal interstitial fibrosis model, lower postoperative mortality and lower incidence of complications in animals as compared with the traditional UUO surgery. The improved UUO group showed statistically significant differences from the sham group in blood biochemical indexes such as urea nitrogen, glutamate aminotransferase, and albumin (P < 0.05). Results from hematoxylin-eosin staining and Masson staining of the obstructed kidney revealed typical pathological features of renal interstitial fibrosis.