Renal effects on a solitary kidney of specific inhibition of cyclooxygenease-2 after 24 h of complete ureteric obstruction in rats.

The purpose of this study is to show whether selective (celecoxib) and non-selective (piroxicam) inhibitors of COX-2 can alter the morphological and functional changes after the release of a 24 h complete ureteric obstruction in tissue from solitary rat kidney. Forty male Sprague-Dawley rats weighing 225-250 g were used. The animals were divided into four groups. In group 1 rats (control, n=10), only right nephrectomy was performed. Group 2 rats (untreated, n=10) underwent right nephrectomy and the left ureter was completely obstructed. In group 3 rats (celecoxib), the same operation was performed as described for group 2 and than celecoxib was administered by gavage for a period of 24 h. Group 4 rats (piroxicam) underwent the same operation as described for group 2, then piroxicam was administered intramuscularly at least 1 h before the release of the for 24 h complete ureteric obstruction. All animals were then prepared for functional and histopathological studies. The administration of celecoxib produced a significant decrease in blood urea nitrogen levels when compared to the animals receiving piroxicam and the animals with no treatment. Moreover, celecoxib caused a significant decreased in creatinine levels when compared to the untreated group. Urine volume and the urinary sodium values were increased in the celecoxib group when compared with the other groups. The administration of celecoxib and piroxicam caused a significant decrease in the number of interstitial macrophages when compared to the untreated group. The Bowman space was significantly increased in the untreated group when compared with the celecoxib and the piroxicam groups. These studies indicate that celecoxib may be an important factor affecting renal morphological and functional changes after the release of a 24 h complete ureteric obstruction.