356 



HEKMAN O. MOSENTHAL 



TABLE 24 



SCHEME OF PROGRESSIVE IMPAIRMENT OF FUNCTION OF THE KIDNEY BLOOD VESSELS 

 (GLOMERULI) AND THE INFLUENCE THIS HAS UPON THEIR ACTIVITY ACCORDING TO 

 SCHLAYER. (ANY RENAL FUNCTION SUCH AS THE EXCRETION OF UREA, SALT, ETC., 

 APPARENTLY PASSES THROUGH THE SAME PHASES, AS THE CORRESPONDING FUNC- 

 TION BECOMES PROGRESSIVELY INVOLVED) 



hided to under the coefficient of urea excretion and the phthalein test. 

 Such a conception has proved to be most valuable in explaining many 

 of the very complex changes that occur in nephritis, and is by far the most 

 important part of Schlayer's contribution to the study of renal function. 



The excretion of the test substances, not found in the body tissues, lac- 

 tose and potassium iodid, follows a somewhat different course. The elimina- 

 tion of these materials is progressively diminished and there is no period of 

 supernormal urinary discharge as there is in the case of water (see table 

 24). 



The theories of Schlayer and his associates have been severely criticised 

 by a number of authors. These objections have recently been summarized 

 by Volhard. Briefly they are that in the animal experiments the so-called 

 impairment of vascular function is largely, if not entirely, due to a drop 

 in blood pressure and not to changes in the renal vessels, that the experi- 

 ments with the vascular nephritides depress function so quickly that any 

 experimental observation is impossible and that the findings depend more 

 on the rapidity of the effect any toxic substance has upon the kidney than 

 upon the particular renal anatomical unit which may be involved. From 

 the clinical point of view, Volhard is unable to correlate Schlayer's func- 

 tional tests with the very evident anatomical lesions as they exist in some 

 cases. Furthermore, the procedures for the lactose and potassium iodid 

 tests are so cumbersome that their use is precluded as a routine measure in 

 clinical medicine. 



These criticisms may be correct even though any one who has worked 

 with Schlayer's methods can find a plausible interpretation for the find- 

 ings in every case. However, it must be admitted that, the actual demon- 

 stration of what role the glomeruli, tubules and blood vessels play in the 

 production of urine, either in health or disease, has not been accomplished. 

 Therefore, any theory of renal function in nephritis rests on an unsatis- 

 factory physiological basis and can not have our full confidence. The fact 

 that slight renal impairment leads to overfunction and marked involve- 

 ment to curtailment of urinary activity has been proved by many tests with 



