Fundamental studies on renal transplantation. Experimental studies on the renal changes found after the extracorporeal normothermic perfusion of dog kidneys with the auto-, homo- or heterologous blood

Abstract

Since the middle of nineteenth century, the extracorporeal normothermic perfusion of the isolated kidney has already been started by using the heart-lung-kidney preparation. It has been particularly used as a vehicle for the physiological and pharmacological studies. Lately the extracorporeal perfusion of the kidney during the renal transplantation has become necessary for the purpose of preservation of the organ and a number of reports on the functional capacity or viability of the perfused kidney have appeared. However there are very few reports on the renal hemodynamics discussed from the standpoint of transplantation immunity when the isolated kidney was perfused with the auto-, homo-, or heterologous blood.In the present paper the author used the extracorporeal perfusion apparatus (MERA C type roller pump, disc type oxygenator) for the perfusion of isolated kidneys and tried to produce an identical experimental condition each time in order to avoid several technical problems and specific or unspecific vital reactions occurring during the renal transplantation. Each of isolated dog kidneys was perfused with the auto-, homo-, or heterologous blood; 3, 7, and 4 cases respectively. The perfusate consisted of the auto-, homo-, or heterologous blood 350ml, 20% mannitol 100ml, aminophyllin 1.0g and heparin 50mg. The changes in those kidneys were investigated by using the autologous blood perfused group as a control and the following results were obtained.1) The renal blood flow obtained from the group perfused with the autologous blood was within a range of 117-171.4ml/100g tissue/min, which was the highest among the three groups. That of the group perfused with the heterologous blood was within a range of 20-84.2ml/min, which was the lowest of all. The group perfused with the homologous blood showed three types of blood flow; high and low flow rates similar to those shown by the previous two groups and the intermediary flow rate between those two. The renal blood flow of all groups tended to decrease as the perfusion proceeded and the kidneys which showed less blood flow at the initiation of perfusion had a tendency to lower the blood flow more rapidly than others. When the blood flow was high enough, the arterial blood pressure of the perfused kidney stayed stable at a relatively low range (around 100mmHg), but in others the pressure inclined to increase as the time passed.2) The hemagglutination reaction tested by blood cross matching was positive in four out of seven cases perfused with the homologous blood and in three out of four cases perfused with the heterologous blood. Of the homologous blood perfused group two cases, which showed a type of high renal blood flow and its gradual decrease by time similar to those seen in the autologous blood perfused group were found to be hemagglutination reaction negative.3) Although the urine flow of the perfused kidneys showed variable changes, the flow was maintained above 5ml/100g tissue/min in the cases perfused with autologous blood and was below 3ml/100g tissue/min in most of the cases perfused with the homologous blood. The urine flow from the kidneys perfused with the heterologous blood, however, was within 3.5-4.5ml/100g tissue/min, showing a range between the two previous ones.4) The osmotic pressure clearance values of perfused kidneys showed excellent correlation to the urine volumes in all groups.5) Throughout the experiment the weight gains of perfused kidneys were between 20-60%, but no significant difference in the rate of weight gain was noticed among the groups.6) Although there were some differences among the groups, the general histological changes found in the perfused kidneys in all groups were turbidity, swelling and vacuolar degeneration of the proximal tubules, some tubular dilatation and interstitial edema. There were noticeable differences in the glomerular changes among the groups, showing a slight change in the autologous blood