FORMATION OF GLYCOGEN. 397 



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 meager. 



If the proteins are to be counted, and this is in agreement with the 

 generally accepted view, among those bodies which 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? t 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 certainty, and the 

 investigations on this subject by different experimenters have given 

 varying results. The experiments of KtJLZ, 1 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 glucose seem to indicate a glycogen 

 formation from sugar in the muscles. The investigations of DE FILIPPI 2 

 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 

 directly into the vena cava without passing through the liver. In 

 well-nourished animals, operated upon in this manner, the livers had the 

 same properties as those from starving animals, while, on the contrary, 

 the muscles contained quantities of glycogen which corresponded to 

 those found in a normal over-fed dog. 



If it be true that the blood and lymph contain a diastatic enzyme 

 which transforms glycogen into sugar, and also that the glycogen regularly 

 occurs in the form-elements and is not dissolved in the fluids, it seems 

 probable that the glycogen in solution is not transmitted by the blood to 



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

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

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



