350 CHEMICAL COMPOSITION OF THE LIVER-CELLS. 



place is taken by newly-formed connective tissue and bile ducts (Charcot and 

 Gombault). In all these cases of interstitial inflammation, there is proliferation of 

 the epithelium of the bile ducts (Foa, Salvioli). 



174. Chemical Composition of the Liver-Cells, 



(1.) Proteids^ The fresh soft parenchyma of the liver is alkaline 

 in reaction; after death, coagulation occurs, the cell contents appear 

 turbid, the tissue becomes friable, and gradually an acid reaction is 

 developed. This process closely resembles what occurs in muscle, and 

 is due to the coagulation of a myosin-like body, which is soluble during 

 life, but after death undergoes spontaneous coagulation (P16sz). The 

 liver contains other albuminous bodies ; one coagulating at 45C, another 

 at 70C, and one which is slightly soluble in dilute acids and alkalies. 

 The cell nuclei contain nuclein (P16sz). The connective tissue yields 

 gelatin. 



(2.) Glycogen or Animal Starch 1-2-2-6 p.c. is most closely 

 related to inulin, is soluble in water, but diffuses with difficulty, is a 

 true carbohydrate (Cl. Bernard and v. Hensen, 1857), and has the 

 formula 6(C 6 H 10 5 ) + H 2 (Kiilz and Borntrager). It is stored up 

 in the liver-cells (Bock and Hoffmann), in amorphous granules around 

 the nuclei, but it is not uniformly distributed in all parts of the liver 

 (v. Wittich). Like inulin, it gives a deep red colour with solution of 

 iodine in iodide of potassium. It is changed into dextrin and sugar 

 (p. 294) by diastatic ferments, and when boiled with dilute mineral 

 acids, it yields grape-sugar. 



Preparation of GlyCOgen. Let a rabbit have a hearty meal, and kill it 

 three or four hours thereafter. The liver is removed immediately after death; 

 it is cut into fine pieces, plunged in boiling water and boiled for some time 

 in order to obtain a watery extract of the liver-cells. [It is placed in boil- 

 ing water to destroy the ferment present in the liver, which would transform 

 the glycogen into grape-sugar.] To the cold filtrate are added alternately dilute 

 hydrochloric acid and potassio-mercuric iodide as long as a precipitate occurs. The 

 albuminates or proteids are precipitated by the iodine compound in the presence of 

 free HC1. It is then filtered, when a clear opalescent fluid, containing the glycogen 

 in solution, is obtained. The glycogen is precipitated from the filtrate, as a white 

 amorphous powder, on adding an excess of 70-80 p.c. alcohol. The precipitate is 

 washed with 60 p.c., and afterwards with 95 p.c. alcohol, then with ether, and 

 lastly, with absolute alcohol; it is dried over sulphuric acid and weighed (Briicke). 



Conditions which influence its amount. If large quantities of starch, 

 milk-, fruit-, or cane-sugar, or glycerine, but not mannite or glycol 

 (Luchsinger), or inosite (Kiilz), be added to the proteids of the food, 

 the amount of glycogen in the liver is very greatly increased (to 12 

 p.c. in the fowl), while a purely albuminous or purely fatty diet 

 diminishes it enormously. During hunger, it almost disappears (Pavy 

 and Tscherinoff). The injection of dissolved carbohydrates into a 



