GLYCOGEN AND GLUCOSE IN THE LIVER. 231 



experimenters. Dock found, in his experiments on the rabbit, 1 that after 

 from 3 to 5 days' fasting the glycogen in the entire liver was reduced 

 to a very minute quantity, or more frequently was entirely absent. 

 But if, in this condition, a solution of glucose were introduced into the 

 stomach through a catheter, and the animal killed from 19 to 24 hours 

 afterward, the quantity of glycogen contained in the liver amounted to 

 from 0.650 to 1.243 grammes. After even t days' fasting, followed by 

 an injection of glucose into the stomach, so short a time as four hours 

 was sufficient to produce an abundance of glycogen in the liver. The 

 deposit of this substance accordingly takes place so rapidly after the 

 ingestion of this kind of food, that no doubt can remain of its being 

 directly produced from the materials of the saccharine or starchy sub- 

 stances. 



Tscherinow showed, by his observations on fowls, 2 both the production 

 of glycogen from animal food, and also its more abundant deposit under 

 a vegetable diet. He found that, in this species, two days 7 fasting was 

 sufficient to reduce the quantity of glycogen to a minimum. After 

 being subjected to a preliminary fast of this duration, the fowls were 

 fed for two or three days with different kinds of food, and then killed 

 and examined. The average results were as follows : 



PRODUCTION OF GLYCOGEN IN FOWLS UNDER DIFFERENT KINDS OF DIET. 

 Diet previous to the Glycogen in the fresh 



experiment. liver, per cent. 



Fasting, 2 days 0.57 



Lean meat, 2 to 4 days ....... 1.40 



Barley, 2 days 5.41 



Kice, 2 days 7.21 



Fibrine and sugar, 2 to 3 days 10.20 



It appears furthermore from the experiments of Weiss and Luch- 

 singer 3 that a similar increase of glycogen will take place in the liver 

 after the ingestion of glycerine (C 3 H 8 O 3 ), a substance closely related in 

 chemical composition to the carbohydrates, but not under the use of fat 

 or of the alkaline tartrates or lactates. 



There is accordingly every reason for the belief that the carbohydrates, 

 when taken in with the food, are at once transported to the liver by the 

 portal circulation, and there fixed in its substance under the form of 

 glycogen. It makes no difference, in this respect, whether these sub- 

 stances be taken as starch or as sugar ; since starchy matters are always 

 transformed into glucose by the process of digestion, to be afterward 

 absorbed by the bloodvessels of the intestine. It is under the form of 

 glucose, therefore, that they all enter the portal circulation and thus 

 reach the tissue of the liver. The process of the conversion of this sub- 



1 Archiv fur die Gesammte Physiologic. Bonn, 1872, Band v. 571. 



2 Archiv fur Pathologische Anatomic und Physiologic, 1869, Band xlvii. p. 102. 



3 Archiv flir die Gesammte Physiologic, 1873, Band viii. p. 290. 



