Accumulation of nitrogen in the tissues in renal disease

Abstract

The retention of nitrogen as a manifestation of certain types of renal disease is a well-recognized phenomenon. When the conditions of study are carefully controlled with accurate analyses of the food and excreta the amounts of nitrogen retained in the body is, with severe cases, very large—two grams per day for periods of two weeks is not an exceptional amount. Since these patients are usually quite sick and commonly manifest no sign of improvement so long as the retention persists it is inconceivable that this nitrogen is retained for tissue growth in a physiological sense. On the other hand while the blood of these patients often shows on analysis an increase in non-protein nitrogen the figure may not rise to any significant degree and never becomes sufficiently high so as to account for more than a small fraction of the nitrogen retained. We have also noted with several patients during metabolism studies a flushing out of nitrogen so that there resulted large minus balances during periods of improvement in the patient's condition. It seemed that the explanation of these phenomena is that the tissues withdraw from the blood a large part of the katabolic products which compose the retained nitrogen and that this would be disclosed by analyses of organs and tissues obtained at autopsy.

For over two years we have been making these analyses as opportunity presented. Certain technical deficiencies are met with which make the accuracy of these results only comparative. The chief among these is due to the fact that as soon as tissues such as liver are minced a separation of fluid (blood and lymph) occurs. This is not the case with muscle but is to some degree true with all organs.