424 THE GLANDULAR ORGANS. 



Ferments. Thus far the following tissue-ferments have been 

 demonstrated in the liver-cell : a maltase, a glucase, a proteolytic fer- 

 ment, a nuclease, an aldehydase, a laccase, a ferment which is capable 

 of transforming the firmly united nitrogen of the amino-acids into 

 ammonia ; further, a fibrin- ferment, one which effects the transforma- 

 tion of glycogen to glucose, a powerful esterase, viz., a lipase which 

 splits especially the lower esters, and finally a rennin-like ferment, 



In addition the liver contains a substance, possibly a preferment, 

 which when activated by a certain principle obtained from the 

 pancreas (a kinase) is capable of causing extensive glucolysis. To 

 be sure, the glucose of the liver disappears of itself when the organ 

 is removed from the body, but we may well imagine that this is 

 owing to the presence of a certain amount of the kinase. Liver- 

 tissue to which pancreas is added will hydrolize a much greater 

 amount of glucose than liver-tissue alone can do (Hirsch). The 

 conditions here are thus quite similar to what takes place in the 

 carbohydrate metabolism of muscle-tissue. 



An antithrombin which inhibits the action of the fibrin-ferment has 

 further been described (see Blood-coagulation). 



Glycogen. Amount. The amount of glycogen which occurs in 

 the liver is primarily dependent upon the state of nutrition of the 

 animal and the amount of exercise that is taken. This is apparent 

 from the fact that it is constantly consumed during the activity of the 

 muscle-tissue more especially, but is also utilized in the regeneration 

 of all cellular elements of the body. During starvation it rapidly 

 disappears, but it is also rapidly formed if carbohydrates are then 

 ingested. Maximal amounts, according to Kiilz, are found after 

 from fourteen to sixteen hours following the administration of food. 

 It has been calculated that in the liver of man 150 grammes can be 

 stored at one time. This would correspond to about 10 per cent, 

 for an organ weighing 1500 grammes. In dogs which have been 

 fed on potatoes and bread Pavy claims to have found as much as 17 

 per cent. After death the transformation of glycogen into glucose 

 continues as in the case of muscle-tissue, and in order to ascertain 

 the exact amount which was present during life it is hence necessary 

 to remove the organ at once and to prevent the further inversion of 

 the material, by the living protoplasm or the contained ferments, by 

 placing the tissue in boiling water. 



Properties. The pure substance represents a white, amorphous 

 powder, which is both odorless and tasteless. In water it forms an 

 opalescent solution, from which it can be precipitated by the addi- 

 tion of alcohol, after adding a little sodium chloride, or by means 

 of lead subacetate. The substance is dextrorotatory. The specific 

 degree of rotation, however, seems to be influenced by various 

 factors. In pure solution it is given as -+- 196.63. It does not 

 reduce Fehling's solution, but can maintain cupric hydroxide in 

 solution. After the addition of a little sodium chloride its solutions 

 are colored red by treating with iodine. With benzoyl chloride, in 

 the presence of sodium hydrate, it gives a granular precipitate of 



