426 THE GLANDULAR ORGANS, 



Extractives. The extractives which are found in the liver, 

 aside from glycogen and glucose, are notably xanthin-bases, which 

 are derived from the nuclei. They comprise xanthin, hypoxanthin, 

 guanin, and adenin. Conjointly they represent about 4.52 pro mille 

 of the dried tissue. They can be isolated, according to the method 

 described on page 391. In addition we find small amounts of urea, 

 uric acid, paralactic acid, and jecorin. Cystin also has been isolated 

 from the normal liver of a horse and from that of the porpoise, but 

 it is questionable whether the substance can actually be regarded as 

 a normal constituent of the gland. It has once been obtained from 

 the liver of a patient who during life had eliminated cystin in the 

 urine. Under pathological conditions, and especially in acute yellow 

 atrophy, large quantities of paralactic acid have been found, in 

 addition to a notable amount of leucin and tyrosin. In amyloid 

 degeneration of the organ chondroitin-sulphuric acid has been 

 observed. Biliary pigments are normally not encountered in the 

 liver-cells, but quite commonly they stain these an intense yellow in 

 cases of obstructive jaundice. These various constituents have been 

 studied in the foregoing chapters, and need not be reconsidered at 

 this place. 



The Digestive Glands. 



Our knowledge of the chemical composition of the digestive 

 glands, viz., the salivary glands, the glands of the stomach, the in- 

 testinal mucosa, and the pancreas, is largely expressed in what has 

 been said regarding their specific secretions. With the exception of 

 the pancreas, the cellular elements proper have not been studied in 

 detail. 



In the pancreas a highly complex nucleoproteid occurs, which on 

 boiling with water yields a second body of the same order, which, 

 however, is of simpler composition. The first is known as Ham- 

 marsten's nucleoproteid-, the second as the corresponding -/? prod- 

 uct. Elementary analysis of this /? product has given the following 

 results : C = 34.0 ; H = 5.0 ; N = 0.7 ; P = 4.5. In addition the 

 substance contains a considerable amount of iron. Both products 

 contain a pentose group ; from the a- body Grund obtained 6.25 per 

 cent., and from the derived body amounts varying between 9.2 and 

 15.4 per cent. 



On digestion with pepsin-hydrochloric acid a nuclein remains 

 behind which is very rich in phosphorus. This yields a nucleinic 

 acid, which Bang has termed guanylic acid from the fact that on 

 decomposition only one purin base, guanin, is obtained. 



Isolation of Guanylic Acid (Bang). 1000-1200 grammes of 

 pancreas (from the ox) are finely hashed and suspended in two liters 

 of 1 per cent, sodium hydrate solution. After standing for twenty- 

 four hours the mixture is heated until it becomes a thin liquid ; 

 acetic acid is then added until the reaction is distinctly acid. The 

 brownish-black precipitate which results is collected and boiled out 



