492 VICTOR C. MYERS 



readily eliminated of the three nitrogenous waste products, uric acid, urea 

 and creatinin, and it is only in chronic nephritis or acute nephritis with 

 partial or complete suppression of urine that retention occurs. A hlood 

 content of more than 5 mg. of creatinin to 100 e.c. has been found to be a 

 very unfavorable prognostic sign (see preceding article, p. 441), 



The excretion of creatinin has been found to be increased in fevers-^- 

 typhoid, pneumonia and erysipelas. Here the rise in temperature is 

 followed by a corresponding rise in the creatinin output. Myers and 

 Volovic have shown that the excretion of creatinin follows closely the 

 rise in temperature during fever, whether the hyperthermia is of infective 

 origin or artificially induced. From this it would appear that the rise in 

 the creatinin elimination was due entirely to the hyperthermia. 



That the creatinin of the urine has its origin in the creatin of the 

 muscle would seem obvious on a priori grounds, but a definite proof of 

 this hypothesis has been beset with many difficulties. The older inves- 

 tigators stated that both administered creatin and creatinin reappeared 

 in the urine as creatinin. When Folin first reinvestigated this question 

 with accurate methods and pure creatin and creatinin, he found that 80 

 per cent of the administered creatinin did reappear as creatinin, but that 

 when creatin was given in moderate amounts (1 gram to man) it not 

 only failed to reappear as creatinin, but completely disappeared. From 

 this Folin quite naturally concluded that creatin and creatinin were rela- 

 tively independent in metabolism. In 1913 Myers and Fine(c) called 

 attention to the fact that the creatin content of the muscle of a given 

 species of animals was very constant (obviously also that of a given 

 animal) and suggested this as a possible basis of the constancy in the 

 daily elimination of creatinin first noted by Folin. Later they pointed 

 out that the creatinin content of muscle was greater than that of any other 

 tissue, and also that in autolysis experiments with muscle tissue the 

 creatin (and any added creatin) was converted to creatinin at a constant 

 rate of about 2 per cent daily, which is just about the normal ratio 

 between the muscle creatin and urinary creatinin. They also found, as 

 did Rose and Dimmitt, Lyman and Trimby, and others, that when creatin 

 was administered to man or animals, there was a slight conversion to 

 creatinin although a considerable percentage of the creatin reappeared in 

 the urine unchanged if large amounts were given. These facts all go to 

 support the view that creatinin is formed in the muscle tissue from creatin, 

 and at a very constant rate, although no explanation of the physiological 

 significance of this transformation can as yet be offered. Excepting 

 possibly the kidney, the muscle normally contains more creatinin than 

 any other body tissue and is followed by the blood which indicates that 

 after its formation in the muscle the creatinin is carried to the "kidney 

 by the blood stream. 



