Unilateral ureteral obstruction.

UUO was performed on 8- to 10-wk-old male mice as previously described (17). Briefly, under anesthesia, the right kidney was exposed dorsally via a flank incision, and two sutures were placed on the ureter just distal to the renal pelvis. The same procedure was performed for the sham-operated mice without obstruction of the ureter. Mice were euthanized at 1, 3, 6, 10, or 14 days after surgery.