Histopathological and functional effects of radiation therapy in obstructive uropathy

Leukocyte influx into the cortex and medulla of the kidney is seen following acute ureteral obstruction. To investigate the macrophage influx and alterations in glomerular filtration rate (GFR) and to evaluate the effects of early radiation therapy on these parameters, we evaluated 20 rabbits in four groups. In the first group preoperative technetium-99m scanning preceding bilateral ureteral complete obstruction was performed. All rabbits received whole body irradiation of 1316 rads. Then the bilateral ureteral obstruction was released after 24 hours. Two hours after releasing, the last scanning was performed. The kidneys were immediately removed and histopathological examination was done. In the second group, all procedures except radiotherapy were done. The third group underwent sham laparotomy to assess the effects of surgical trauma on renal functions. The fourth group of rabbits was considered as control. We have observed an apparent macrophage influx into the cortex and medulla of the kidney following bilateral ureteral obstruction (p=0.000). However, irradiation reduced the infiltration significantly (p=0.000). Also in cases who received radiotherapy GFR was preserved to a significantly higher degree (p=0.000). We concluded that irradiation following acute ureteral obstruction has protective effects on renal function through abolition of the infiltrating cells.