METABOLISM IN NEPHRITIS 



321 



TABLE 4 



TISSUE ANALYSES IN A CASE OF CHRONIC INTERSTITIAL NEPHRITIS DYING OF UREMIA. 



(Myers and Fine, 1915) 



closely. This is perhaps more strikingly brought out by the very complete 

 set of analyses in a most interesting case of Myers and Fine (1915) (see 

 Table 4). In this instance it may be noted that the urea, creatinin and 

 uric acid are equally distributed except in the spinal fluid. As far as the 

 urea is concerned such a result is only to be expected according to the work 

 of Marshall and Davis. The creatin is in an entirely different relation than 

 the other substances. Under normal conditions the highest creatin values 

 are found in the muscle; this apparently is also true in nephritis; when 

 the creatin is found in excess in the blood, it must be derived from the 

 muscular tissue and has been regarded as a sign of an abnormal degree of 

 protein disintegration. It would appear, therefore, that with the excep- 

 tion of the creatin, the non-protein nitrogenous constituents may be con- 

 sidered to be fairly evenly distributed throughout the body (excepting 

 of course the fat, bones, cartilage and teeth) and that the values obtained 

 by an analysis of the blood furnishes a true indication of what has oc- 

 curred in the tissues. 



The Urea of the Blood in Nephritis 



The urea of the blood is the most used of the chemical tests resorted 

 to for information regarding the retention of non-protein nitrogenous con- 

 stituents in nephritis. This is because the estimation of this substance 

 is more rapid, easier to carry out and possibly more accurate than is the 

 case with the other compounds containing nitrogen. There is one other 

 fact that must be kept in mind when the results for urea are valued. 

 In large part the level of the urea in the blood is controlled by what are 

 termed the exogenous factors; that is, the amount of protein food in- 

 gested will control it to some extent. This is not only an immediate effect, 

 but one which lasts for some time. Thus in a group of 5 normal indi- 

 viduals, the blood urea nitrogen varied between 4.5 and 9.0 mg. per 100 



