CHEMICAL CHANGES OF ACUTE YELLOW ATROPHY 447 

 CHEMICAL CHANGES OF ACUTE YELLOW ATROPHY 



The Urine. Most striking, and long regarded as pathog- 

 nomonic, is the presence of leucin and tyrosin in the urine, first 

 described by Frerichs. While we now know that these and 

 other amino-acids may occur in the urine in any conditions 

 where there is a great breaking down of tissue within the body, 

 yet it is true that in no other condition are they found so abun- 

 dantly as in acute hepatic atrophy (as high as 1.5 gm. of tyro- 

 sin per diem has been found 1 ). They are nearly constantly 

 present (in thirteen out of fourteen cases studied by Biess 2 ), 

 tyrosin being usually the more abundant. Deutero-proteose is 

 also frequently (but not constantly) found, as further evidence of 

 abnormal proteid splitting. 3 Uric acid and other purins are 

 often somewhat, but not characteristically, increased, probably 

 resulting from the nuclear destruction in the liver. The total 

 elimination of nitrogen is increased 4 (particularly if the scanty 

 intake is considered), and the proportion that appears as urea is 

 decreased, largely because of the presence of much ammonia, 

 part of which, at least, is eliminated combined with organic 

 acids. Chief of these acids is sarcolactic acid, but of particular 

 interest is the appearance of oxymandelic acid, 



COOH, 



which is apparently derived from tyrosin, 



HO/ \CH 2 CH(NH 2 ) COOH, 



by the splitting out of the NH 2 group, the benzene nucleus 

 failing to be completely oxidized, as is normally the case. It is 

 evident from the urinary findings, therefore, that oxidation is 

 decreased, which is presumably because of the destruction of liver 

 tissue with its important oxidizing functions. The reduction of 

 oxidation can also be shown experimentally by studying the 

 respiratory exchange, Welsch 5 having found the oxidation 



1 An interesting exception has been reported by W. G. Smith (Practitioner, 

 1903 (70), 155) who found great quantities of leucin in the urine of a young 

 woman who was apparently not at all ill. 



2 Berl. klin. Woch., 1905 (42), No. 44 a., p. 54. 



3 Salkowski (Berl. klin. Woch., 1905 (42), 1581) found in the urine of a case 

 of acute yellow atrophy a large quantity of nitrogen in a colloidal but non- 

 proteid form, apparently of carbohydrate nature. Mancini (Arch, di farm, 

 sperim., 1906, Bd. v) also observed an increase in the colloidal nitrogen of 

 the urine in liver diseases. 



4 See Welsch, Arch. int. pharm. et The*r., 1905 (14), 211. 



5 Loc. cit. 



