646 LOUIS BAUMAN 



jected into a dog they accumulate in all the tissues, but disappear most 

 rapidly from the liver, coincident with an increase of the urea concentra- 

 tion in the blood. Van Slyke, Cullen and McLean have shown that the 

 urea content of the blood of the hepatic veins is from 2 to 20 per cent 

 higher than that of the portal vein. A similar elevation of the urea con- 

 tent in the blood that had passed through muscle did not occur. 



By virtue of its ferment arginase (Dakin and Kossel) the liver is 

 able to directly convert arginin into urea and ornithin. 



HN"-CH 2 CH 2 CH 2 CHNH 2 COOH+H 2 O=NH 2 CO 

 CH 2 CH 2 CH 2 CHiNH 2 COOH. 



The synthesis of amino acids from keto acids by the surviving liver has* 

 been demonstrated by Embden and Schmitz(a)(6). These authors found 

 that pyruvic acid was converted into alanin, phenylpyruvic acid was con- 

 verted into phenylalanin and hydroxyphenylpyruvic into tyrosin. Alanin 

 was also obtained when ammonium chlorid was perfused through a glyco- 

 gen rich liver (Fellner). The liver therefore can synthesize amino acids 

 from carbohydrate derivatives and ammonia and this may account, in part 

 at least, for the sparing action of carbohydrates on protein metabolism. 



Recent observations indicate that the liver is also concerned with the 

 formation of fibrinogen. 



The Detoxicating Function of the Liver. The liver is partly con- 

 cerned with the detoxication of poisonous substances absorbed from the 

 intestine. The action of intestinal bacteria on proteins results in the 

 formation of phenols, indole derivatives and amines, and these are absorbed 

 and brought to the liver where they are chemically altered into harmless 

 substances, either by oxidation or by conjugation, or by both processes. 

 Phenols are directly combined with sulphuric acid, while indol is first 

 oxidized to indoxyl and .then united with sulphuric acid. These com- 

 pounds are excreted by the kidneys and constitute the ethereal sulphate 

 fraction in the urine. In Eck fistula dogs the sulphur partition in the 

 urine is normal (Lade), and if cresol or indol is administered, an increase 

 of the ethereal sulphate fraction results; therefore it is improbable that 

 the liver is alone concerned with the formation of ethereal sulphates. 

 Herter and Wakeman have shown that hashed liver tissue disposes of 

 indol and phenol to a greater extent than other organs. Embden and 

 Glaessner found that the surviving liver of the dog can synthesize ethereal 

 sulphates, though the lungs and kidneys also possess this power to a lesser 

 degree. The liver detoxicates benzoic acid by uniting it with glycocoll to 



