CKEATIN AND CEEATININ 177 



From the foregoing one might conclude that creatinuria regularly 

 accompanies undernutrition, whatever the cause. This is actually the case. 

 Diabetes, carcinomatosis, hyperthyroidism, fevers, incessant vomiting and 

 other wasting conditions are usually accompanied by the appearance of 

 creatin in the urine. Feeding thyroid substance increases the metabolic 

 rate and leads to the elimination of creatin (Krause and Cramer) . Shaffer 

 (a) (1908) found that of 10 cases of hyperthyroidism 8 exhibited creatin 

 in the urine. Denis (/) (1917) has shown that the creatin excretion in this 

 condition is increased by feeding a high protein diet. As hydroxbutyric and 

 acetoacetic acids often accompany creatin in the urine it has been supposed 

 that a causal relationship exists between acidosis and creatin excretion. 

 Underhill (fc) (1916) noted that rabbits began to excrete creatin when they 

 were fed on acid producing diets or when hydrochloric acid itself was 

 administered. In both series of experiments the supply of carbohydrates 

 was sufficient and the protein per se was without influence. Underhill (I) 

 (1916) also found that the administration of alkalies diminished the 

 creatin output during the early days of starvation. In phlorhizin glyco- 

 suria, however, alkali administration was without effect (Underhill and 

 Baumann). McCollum and Hoagland (a) (1913) observed that pigs elim- 

 inated creatin when fed on fats, water and neutral salts, but failed to do 

 so when the salts were alkaline. Considering all the known facts per- 

 taining to this phase of the subject it appears unwise at present to assume 

 a causal relationship between acidosis and creatinuria. 



Creatinin Metabolism 



Muscle. Skeletal muscle contains from 5 to 15 mgs. of creatinin per 

 100 grams of moist tissue (Myers and Fine (i), 1915 ; Folin and Denis (</), 

 1914), that is, from 5 to 10 times the amount which is present in the 

 blood which circulates through it. Shaffer (6) (1914) holds that this is an 

 argument in favor of the view that creatinin is formed in muscle tissue. 

 The rate of conversion of creatin into creatinin in autolyzing muscle is 

 proportional to the temperature and is 3 times more rapid than in watery 

 solution. 



Blood. The blood of normal individuals contains from 1 to 2 mgs. 

 of creatinin per 100 c.c. (Folin and Denis (#), 1914). In nephritis rela- 

 tively large quantities, as much as 33 mgs. have been reported. In patho- 

 logic conditions of the kidney uric acid and urea are retained before crea- 

 tinin and elevations of the last above 5 mgs. indicate a grave prognosis 

 except in acute renal inflammations (Myers and Lough). 



Urine. In a classical article published in 1905, Folin showed that the 

 excretion of creatinin on a meat free diet was constant for each individual 



