560 SAMUEL H. HURWITZ 



bile fistula dog with bile-pigment excluded from the intestine (Hooper(a) ). 

 Under such circumstances the absorption of any pigment substances (bile- 

 pigment, urobilin or urobilinogen) from the intestine is out of the ques- 

 tion. It does appear, however, that under certain conditions as in acute 

 regeneration following anemia, the body may conserve the substances 

 which are suitable for the elaboration of hemoglobin (pyrrol nucleus). 

 Evidently the pyrrol complex is a peculiar feature of the hemoglobin 

 molecule, which the body carefully conserves for the purpose of recon- 

 structing the hemoglobin molecule. 



Whether the building stones which go to make up the hemoglobin 

 molecule may arise also from certain elements of protein catabolism is 

 not known. From the available experimental evidence, it would appear 

 that both the products of protein catabolism as well as certain factors in 

 the diet contribute to the steady construction of hemoglobin pigment. 



The demonstration that the curve of hemoglobin regeneration can be 

 influenced by various diet factors (Whipple and Hooper(a) (6), and 

 Hooper, Robscheit and Whipple(a) (6) (c)) is very interesting and of the 

 greatest significance in the treatment of anemia in man. It has 

 been shown, for instance, that meat protein (beef, beef heart) and 

 liver give a maximum hemoglobin production, whereas certain car- 

 bohydrates (bread, milk, crackermeal, rice, potato) or some of their 

 ingredients, such as casein and gliadin give a minimum curve of pigment 

 regeneration. On the other hand, gelatin or its mono-amino acid frac- 

 tion, and hemoglobin itself administered either by mouth, intravenously, 

 or intraperitoneally exert a distinctly favorable influence upon blood re- 

 generation. Contrary to expectation, it has been found further that 

 sugar feeding is less favorable for hemoglobin regeneration than is starva- 

 tion. It is believed by Whipple and his co-workers that this observation 

 may be explained by the protein-sparing action of sugar. Under condi- 

 tions of starvation, the body may conserve certain substances resulting 

 from the breaking down of body protein and use them over again in the 

 construction of hemoglobin. 



These studies on the relation of liver cell activity to the metabolism 

 of blood-pigments indicate that the liver has a more important blood- 

 building function in adult life than has hitherto been ascribed to it. 

 Upon its functional activity depends not only the level of bile-pigment 

 and hemoglobin production in the body, but there is much experimental 

 evidence that its functional integrity is concerned with the maintenance 

 of a normal level of plasma (Whipple, Meek(a)(&)) and serum proteins 

 (Kerr(a) (&)(c)). In these instances, also, has evidence been produced 

 that this particular activity of the liver may be modified by the materials 

 brought to it not only from the products of tissue catabolism but also from 

 certain substances in the diet. 



