ITS LOUIS BAILMAN 



and independent of the exogenous metabolism and the total nitrogen ex- 

 cretion. Shaffer (a) (1908) confirmed these observations and found that 

 the hourly excretion of creatinin was also uniform. This constancy of cre- 

 atiniri elimination has been used to control the accuracy of the 24-hour 

 urine collection. The daily creatinin excretion for an adult man lies 

 lx>tween 1 and 2 grams. From the viewpoint of quantity it is second in 

 importance to urea. A normal man excretes between 7 and 11 nigs, of 

 creatinin nitrogen per kilo of body weight ; this has been named the 

 creatinin coefficient by Shaffer () (1908). It is apparently a function of 

 the mass of active muscle tissue for stout and elderly people, and women 

 often have values below 7 7. The coefficient of the dog averages 8.4. Myers 

 and Fine (c) (1013) have studied the relation of the creatinin coefficient to 

 the total creatin content of the body. In the case of the rabbit this is 

 quite constant, averaging 44.7 ings, of body creatin to 1 of creatinin in 

 the urine. The daily output of creatinin represents a conversion of about 

 2 per cent of the total creatin present in the body. The creatin content 

 of the rabbit per kilogram is about one-third higher than that of man, and 

 its creatinin coefficient is proportionately higher, that is, 14. 



The creatinin excretion of women is lower than that of men. Tracy 

 and Clark found the average creatinin coefficient of 26 women to be 5.8. 

 According to these authors the low coefficient of women is due to 

 their relatively inferior muscular development. Hull found the average 

 creatinin excretion to range between 670 and 880 nigs. Muscular activity 

 has no effect on creatinin excretion (Van Hoogenhuyze and Verploegh (&), 

 1008; Shaffer (a), 1908). 



During starvation there is a gradual decrease in creatinin in the 

 urine along with an increase in creatin (Cathcart (a) 5 1907; How r e, Mat- 

 till and Hawk (b) ; Hunter, 1914). Pigs that were fed on a liberal amount 

 of carbohydrate, salts and water reached a stage when the creatinin ac- 

 counted for 18 per cent of the total nitrogen in the urine (McCollum and 

 Hoagland (#), 1013). Fevers cause an increase in urinary creatinin 

 (Van Hoogenhuyze and Verploegh (6), 190S ; Klercker (c), 1909 ; Leathes 

 (a)). Myers and Volovic observed that the increase was proportional to 

 the height of the temperature. 



Creatin is often present in the urine in conditions associated with 

 dissolution of muscle tissue, and then the creatinin is usually found 

 to be decreased (Levene and Kristeller). Spriggs reported a very low 

 creatinin excretion in 2 cases of muscular dystrophy and also in a case 

 of amyotonia congenita. In progressive muscular dystrophy, McCrudden 

 and Sargent observed large quantities of creatin in the urine with a con- 

 stant creatinin elimination. 



In wasting or atrophy of muscle the creatin eliminated in the urine 

 is probably derived from the disintegrated muscle fibres. 



