Experimental Studies on Cross Circulation between Normal Dogs and Dogs with Disturbed Kidney Function: Part II. Influence of Cross Circulation on Non-Protein Nitrogen, Urea Nitrogen and Creatinine Blood Levels of Nephrectomized Dogs

Moon, Hyo Joong; Lee, Hak Song

Abstract

In the first paper of this experiment, the author reported no significant changes in NPN, urea nitrogen and creatinine blood levels resulting from cross circulation between normal dogs. In this experiment cross circulations between Nephrectemized dogs and normal ones were performed and the rate of removal of waste products from the blood of bilaterally nephrectomized dogs through the kidneys of normal dogs as well as the state of improvement of a general condition were observed. Blood levels of NPN, urea nitrogen and creatinine were determined. Sixty to seventy-two hours after both kidneys were removed, the dogs developed anorexia, nausea, vomiting and apathy. Cross circulation as previously described was instituted when blood concentration of NPN varied from 139.2 to 193 mg%; urea nitrogen, from 86.7 to 137.8 mg; and creatinine, from 4.8 to 6.8 mg%. All procedures were carried out under an aseptic technique and penicillin or streptomycin were given to prevent infection. Using the indirect cross circulation in two pairs of dogs, 2080 cc and 3520 cc of blood was cross transfused for periods of 100 minutes and 5 hours respectively. Blood was exchanged by the direct cross circulation in four pairs of dogs for periods ranging from four hours 35 minutes to eight hours. The results obtained are as follows: During cross circulation between the nephrectomized dogs and the normal ones, the former exhibited improvement in their vitality, ceased nausea and vomiting and began to eat. During the indirect cross circulation the NPN of the nephrectomized dogs was lowered 13.8 mg% and 27.2 mg; whereas when using the direct cross circulation a decrease of 57.6 mg% to 84.6mg% and obtained. Decreases in urea nitrogen and creatinine blood concentrations were observed to be 10.2 mg% to 22.6 mg% and O.6 mg% respectively by the indirect cross circulation. whereas 32.7mg% to 65.1 mg% and 2.2 mg% to 3.O mg% respectively by the direct method. The lowered blood concentrations of the waste products, however, rose again and the general condition of the nephrectomized dogs became worse one or two days after the completion of the experiment. The normal dogs receiving blood from the nephrectomized dogs developed a rapid pulse, frequent and irregular respirations, a weakened general condition and elevation of blood concentrations of NPN. urea nitrogen and creatinine. The general condition and the blood concentrations, however, returned to normal one to four days after the completion of the experiments. The direct method of cross circulation between bilaterally nephrectomized dogs and healthy ones is superior to the indirect method in respect to the animals general condition and to the removal of waste products from the blood of the nephrectomized animal.