The Effect of Intravenous E. coli Injection on the Kidney after Ureteral Ligation in the Rat

Kang, Young Il; Lim, Su Kil

Abstract

This study was designed to observe morphological changes of the renal cortex and medulla of the rat kidneys after intravenous Escherichia coli injection following unilateral ureteral ligation. A total of 105 white rats weighing about 180-200g were used in the experiments. Animals were divided into 3 groups: Escherichia coli injection without ureteral ligation (Group I), unilateral ureteral ligation without intravenous Escherichia coli injection (Group II), and intravenous Escherichia coli injection following unilateral ureteral ligation (Group III). Each group consists of 35 rats. In group I, each rat was injected with about 2 X 10 8 Escherichia coli through the tail vein. In group II, each rat was ligated on the left ureter with silk ligature completely. In group III, each left ureter was ligated and 2 X 10 8 Escherichia coli was injected through the vein of rat tail. Kidneys were obtained 4 hour, 1, 3, 5, 7 days, 2 and 4 weeks after injection of E. coli or ligation of ureter. Specimen of the left kidneys were observed with light microscopy stained with hematoxylin-eosin. 1. In group I, pyelonephritis developed from the 3rd day to the 7th day, after intravenous injection of E. coli, After the 7th day pyelonephritis tended to heal spontaneously. 2. In group II, pyelonephritis developed on the 3rd day after ureteral ligation and inflammatory changes were aggravated progressively thereafter. 3. In group III. renal inflammatory changes were more severe and it progressed faster than in group II. 4. In group II and III, the inflammatory changes were more severe in the renal medulla than in the cortex.