Cellular proliferation in the urinary tract epithelium of the rat following temporary unilateral renal ischaemia.

A study of the effect of temporary unilateral renal ischaemia on the epithelium lining the renal pelvis and the bladder of the rat is described. There is a significant increase in the mitotic index in the pelvic epithelium of the affected kidneys, presenting a well-defined peak approximately 36 h after reflow. A similar but less pronounced cellular proliferation occurs in the bladder epithelium. The increased mitotic index in the renal pelvis and the bladder is not preceded by any detectable cell destruction at either site. It also has a different time course from the tubular regeneration which follows renal ischaemia.