METABOLISM IN NEPHRITIS 347 



produced an increase of 1 gram per liter in the plasma within one and 

 one half hours after the administration of large amounts of salt to dogs 

 by stpmach tube. The chlorid content of the plasma returned to its previ- 

 ous level in 24 to 48 hours. Restriction of sodium chlorid in the food 

 of nephritic patients will often reduce an excessive degree of blood chlorids. 

 Thus Myers cites one instance of advanced nephritis in which the sodium 

 chlorid of the whole blood dropped from 5.94 grams to 3.94 grams per 

 liter through suitable dietary restrictions. In normal dogs Austin and 

 Jonas could produce no drop in the plasma chlorid level either by a diet 

 low in salt or by free flushing of the body wifh water. They come to a 

 very interesting conclusion in regard to this matter: "These experiments 

 indicate, therefore, that in those cases of clinical nephritis in which, fol- 

 lowing the use of a low chlorid diet, the plasma chlorids fall distinctly be- 

 low normal, this depression of the plasma chlorids is evidence of disease and 

 not merely a consequence of the patient's regime." 



There are two possible factors that may be of influence in raising 

 the blood chlorids that should be kept in mind from the clinical point of 

 view. First, it is perfectly evident to any one who has listed a series 

 of blood chlorid determinations and compared them to the level of other 

 renal excretory products in the blood, that when renal insufficiency exists, 

 the blood chlorids often rise ; this synchronous occurrence of renal insuffi- 

 ciency and rise in blood chlorids is, however, far from constant. This is 

 not surprising as the kidney may be unable to excrete one substance while 

 it retains another, or the effect of diet may make itself felt. It is only 

 natural to suppose that a poorly functionating kidney will bring about a 

 retention of chlorids, but it must be realized that this explanation does 

 not account for all the variations that apparently occur in the blood 

 chlorids. Second, there is an evident attempt of the body to keep its 

 fluids in osmotic balance; this has already been alluded to in a theory 

 put forth by Atchley when he supposed that the chlorids in the plasma may 

 diminish as the blood urea rises; on this basis the low blood chlorids 

 found in diabetes may be assumed to be caused by the hyperglycemia 

 present in that condition. Another finding which substantiates this idea 

 is the very bizarre and marked fluctuations obtained in the chlorid con- 

 centrations in the blood after the administration of 100 grams of glucose. 

 W. W. Herrick has shown the author some very interesting examples of 

 such observations. The above theories undoubtedly offer an explanation 

 of some of the variations occurring in the blood chlorid concentration; 

 they do not account for them in full and many further observations will 

 Tie necessary before the problem of 'what influences control the chlorids 

 in the blood in nephritis will have been cleared up. 



The subject of chlorids in nephritis is,discussed from another point of 

 view under the heading of the Chlorid Threshold in Nephritis/ in the 

 section on Renal Function. 



