156 



DIASTATIC ACTIVITY IN BLOOD AND URINE. 



The figure obtained in healthy individuals for the diastatic concentration 

 factor lies between 15 and 40. When the figures in the two columns for the 

 urea concentration and the diastatic concentration factor are compared they 

 are found to be in general agreement, normal values of one corresponding to 

 normal percentages of the other, and low values of one corresponding to low 

 percentages of the other. 



Stafford and Addis {loc. cit.) compare the rate of excretion of diastase with 

 the power of the kidney to concentrate urea, and state as a remarkable fact 

 that emphasis has usually been laid on the concentration of diastase, and not 

 on the rate of excretion of diastase. They obtain the rate of excretion or the 

 total hourly diastatic activity by multiplying the amount of urine in c.c. by the 

 urinary diastatic activity (Wohlgemuth units) , and dividing by the time in hours 

 which the kidney took to secrete the specimen considered. In MacLean's 

 urea concentration test stress is laid on the power of the kidney to concentrate 

 urea. In the present investigation stress is laid on the power of the kidney 

 to concentrate diastase from the blood, and not on the rate of excretion as 

 shown by the total hourly diastatic activity. 



It is possible to have (c/. Case 13, Table IX) a normal urinary diastatic 

 activity and total hourly diastatic activity along with a high blood diastatic 

 activity, thus producing a diastatic concentration factor lower than normal. 

 Further, the hourly rate of excretion is found to vary so widely in different 

 normal individuals that the application of the hourly rate of excretion of 

 diastase to abnormal cases would not appear to be justifiable. 



In addition, in the present investigation the diastatic concentration factor 

 is compared in many cases with the urea concentration as obtained by 

 MacLean's test, and in this way conclusions are avoided that depend on a 

 comparison between the urea concentration and the hourly rate of excretion 

 of diastase, which is very variable even in normal subjects. 



