CREATIN-CREATININ ELIMINATION 



125 



cording to the studies of Pekelharing and his associates, 10 

 partly excreted without change, partly excreted after anhy- 

 dration into creatinin; and according to these writers the 

 liver is apparently of importance both in the decomposition 

 and also in the process of dehydration. Besides this mode 

 of destruction, in experiments in which creatin or creatinin 

 has been introduced by the mouth decomposition may take 

 place of either substance from the agency of bacteria in the 

 intestine ; so that it is not at all surprising in such experi- 

 ments if nothing but a fraction of the substances introduced 

 appears in the urine. 11 



Endogenous and Exogenous Distribution of Creatin- 

 Creatinm Elimination. In trying to recognize the precise 

 sources of the urinary creatin and creatinin reference to a 

 recent illuminating presentation of the subject by Lafayette 

 Mendel 12 with the following schema based thereupon may 

 serve to most quickly orient ourselves upon the subject: 



Preformed creatin 

 from meat food 



Protein 



Food Protein Reserve Protein 



i (Circulating Protein) 



I 



Tissue Protein 



Creatin 



Portion Decomposed 

 in Metabolism 



Urinary 

 Creatin 



Urinary 

 Creatinin. 



10 C. A. Pekelharing and C. J. C. Van Hoogenhuyze, Zeitschr. f. physiol. 

 Chem., 69, 395, 1910; cf. also P. A. Levene and L. Kristeller, Amer. Jour, of 

 Physiol., 24, 44, 1909. 



n W. Czernecki (E. S'alkowski's Lab.), Zeitschr. f. physiol. Chem., 44, 294, 

 1905; P. Nawiasky (M. Rubner's Lab.), Arch. f. Hygiene, 66, 239, 1908; R. H. 

 A. Plimmer, M. Dick and C. C. Lieb, Jour, of Physiol., 39, 112, 1909-10. 



12 L. B. Mendel and W. C. Rose, Jour, of Biol. Chem., 10, 249, 1911. 



