118 UREA. HIPPURIC ACID. AMINOACIDS 



Cystinuria and Diaminuria. Our interest in the dis- 

 covery of the aminoacids in the urine has taken on special 

 interest since we have learned to look upon two rare and 

 important metabolic anomalies, cystinuria and diaminuria, 

 as belonging in the same category. 66 It has been known 

 for a long time that cystin is excreted in the urine and may 

 be found in concretions and in urinary sediments in its strik- 

 ing crystalline form (regular hexagonal plates). E. Bau- 

 mann and L. v. Udranzky have recognized in a case of 

 cystinuria the presence of diamines in the urine. In the 

 light of A. Ellinger's investigations, previously considered 

 (v. Vol. I of this series, p. 34, Chemistry of the tissues), 

 there can be little doubt that in such a subject cer- 

 tain of the " building stones" of the protein molecule come, 

 so to speak, to the surface of metabolism which should or- 

 dinarily undergo complete disintegration in its depths ; and 

 that here we have to deal on one hand with the sulphur- 



CH a .S-S-CH 2 \ 

 containing fraction of protein, cystin I CH.NH 2 CH.NH, ), 



^COOH COOH 



and on the other hand with the diamines, putrescin (tetra- 

 methylendiamine CH 2 .NH 2 - CH 2 - CH 2 - CH 2 .NH 2 ) and 

 cadaverin (pentamethylendiamine CH 2 .NH 2 - CH 2 - CH 2 - 

 CH 2 - CH 2 .NH 2 ), the first arising from ornithin and the 

 latter from lysin by separation of C0 2 . Ornithin is, repeating 

 a statement previously made in the present lecture, a cleav- 

 age derivative of arginin. The true significance of cystinuria 

 and diaminuria was first correctly explained by the observa- 

 tions of A. Lowy and C. Neuberg. These writers noted in an 

 individual under their observation that he was unable to 

 oxidize introduced mono- and di-aminoacids, which in the 



M Literature upon Cystinuria and Diaminuria : E. Friedmann, Ergebn. d. 

 Physiol., 1, 16, 1902; F. Umber, Lehrb. d. Ernahr. u. d. Stoffwechselkr., 1909, 

 pp. 385-389; J. Wohlgemuth, Handb. d. Biochem., 3', 192-195, 1900; A. Ellinger, 

 ibid., 5', 660-664, 1910; C. Neuberg, ibid., 4", 338, 1910; C. E. Simon and D. G. 

 Campbell, Johns Hopkins Hospital Bulletin, 15, 365, 1904. 



