376 THE LIVER. 



can be drawn from this on the behavior of the carbohydrate groups, 

 which exist not as free groups but combined with the protein molecules. 

 The investigations of FORSCHBACH on the behavior of glucosamine 

 chained to an acid-group in an amide-like combination, as well as the 

 investigations of KURT MEYER and STOLTE, 1 have yielded no proofs for 

 the theory that glycogen is formed from glucosamine. 



Whether or not, or to what extent, the glucoproteins take part in 

 the sugar or glycogen formation in the animal body is difficult to answer 

 for the present, as but little is known of the quantity of these substances 

 in the body, and our knowledge of the amount of carbohydrate which can 

 be split off from the various protein substances is also very meagre. 



If the proteins are to be counted among those bodies which can 

 increase the glycogen of the body, then we must ask the question: Do 

 the proteins act only indirectly as pseudoglycogen-formers, or are they 

 direct glycogen-formers which can serve as material for the formation 

 of glycogen or sugar? This question stands in close relation to the 

 sugar formation and sugar elimination in the various forms of glycosuria, 

 and will be best discussed below in connection with the question of 

 diabetes. 



Glycogen is a reserve-food deposited in the liver, and which, like other 

 carbohydrates can be transformed into fat, and it is generally admitted that 

 such a fat-formation from glycogen also takes place in the liver. There 

 is no doubt that the glycogen deposited in the liver is formed in the liver- 

 cells from the sugar; but where does the glycogen existing in the other 

 organs, such as the muscles, originate? Is the glycogen of the muscles 

 formed on the spot or is it transmitted to the muscles by the blood? 

 These questions cannot at present be answered with positiveness, and the 

 investigations on this subject by different experimenters have given 

 varying results. The experiments of KtJLZ, 2 in which he studied 

 the glycogen formation by passing blood containing cane-sugar through 

 the muscle, have led to no conclusive results, while the perfusion exper- 

 iments of HATCHER and WOLFF with dextrose seem to indicate a glycogen 

 formation from sugar in the muscles. The investigations of DE FILIPPI 3 

 on dogs with so-called Eck's fistula also show a glycogen formation from 

 sugar in the muscles. In the Eck fistula operation the portal vein is 

 ligated near the liver hilus and sewed to the inferior vena cava and an 

 opening established between the two veins so that the portal blood flows 



1 Fabian, Zeitschr. f. physiol. Chem., 27; Frankel and Offer, Centralbl. f. Physiol., 

 13; Cathcart, Zeitschr. f. physiol. Chem., 39; Bial, Berl. klin. Wochenschr., 1905; 

 Forschbach, Hofmeister's Beit rage, 8; Meyer, ibid., 9; Stolte, ibid., 11. 



2 See Minkowski and Laves, Arch. f. exp. Path. u. Pharm., 23; Kiilz, Zeitschr. f. 

 Biologic, 27; Hatcher and Wolff, Journ. of Biol. Chem., 3. 



3 Zeitschr. f. Biol., 49 and 50. 



