Effect of Bilateral Ureteral Ligation and Bilateral Nephrectomy upon Erythropoietin Activity / 대한비뇨기과학회지

ABSTRACT

It is generally accepted that erythropoiesis is controlled by the erythropoietic stimulating factor (erythropoietin) which is believed being produced in the kidney. Among the various causes. hypoxia is one of the most potent one for the stimulation of erythropoietin production in the kidney. This experiment was planned to determine the efficiency of the erythropoietin in the hydronephrotic kidney and the intact or disturbed liver function. Materials and Methods: The mongrel dogs weighing between 10 and 13 kg were used. Group A: A1: hydronephrosis due to bilateral ureteral ligation. A2: hydronephrosis due to bilateral ureteral ligation and testosterone injection. A3: hydronephrosis due to bilateral ureteral ligation and CCI4 intoxication. Group B: B1' bilateral nephrectomy. B2: bilateral nephrectomy and CCI4 intoxication. To observe the chemical constituents and erythropoietic activity blood sample were collected on 2, 4, 6. 8. 10th day after operation in the A group and 1, 2, 3. 4th day after operation in the B group. Chemical constituents were BUN, creatinine and electrolytes. Erythropoietic activity was determined by the incorporation of 59Fe into the red cells of mouse (DeGowin method). The results of the experiments were summarized as follows: 1. The hydronephrosis due to bilateral ureteral ligation induced increase of erythropoietic activities. 2. When testosterone was given in the group of the hydronephrosis due to bilateral ureteral ligation, erythropoietic activity was increased more than in the group of the hydronephrosis only. 3. The most prominent elevation of erythropoietic activities among any other group was confirmed when liver function was disturbed by CCl4 intoxication in the hydronephrotic animals. This marked elevation seemed to be due to the disturbance of the liver function which inactivated or destroyed erythropoietin. 4. Erythropoietin activity was decreased in the group of bilateral nephrectomy. 5. Erythropoietin activity was much less in the bilateral nephrectcmized group when liver was damaged by CCI. injection. The erythropoietic stimulation was ineffective in the nephrectomized animals. 6. Testosterone injection decreased the BUN and creatinine level in the uremic animals due to nephrectomy. 7. Pathological findings revealed mild hydronephrotic changes in the group of ureteral ligation by. testosterone injection, and mild degree of necrosis and severe fibrosis in the interstitial tissue of the kidney, and fatty changes and focal central necrosis of the liver due to CCl4 injection.