534 DIABETES 



glycogen. Furthermore, in the large majority of cases we do 

 not know the cause of such pancreatic lesions as may be found 

 at autopsy. Sometimes there is evidently a chronic inflamma- 

 tory process in the gland resulting from occlusion or infection 

 of its duct, but usually this form of pancreatitis does not 

 involve seriously the islands of Langerhans or cause diabetes. 

 In the majority of the cases of diabetes in which pancreatic 

 lesions are found the islands seem to be more affected than the 

 other tissues, indeed, they often appear to be specifically 

 affected, and the cause of this attack upon the islands is quite 

 unknown. 



The metabolic processes in diabetes seem also to be disturbed 

 in quite the same way as after pancreatectomy, except in respect 

 to the interference with digestion in the pancreatectomized 

 animals because of the total absence of the pancreatic juice. 

 (However, in some cases of human diabetes the pancreatic 

 changes are so extensive as to interfere with the secretion of 

 pancreatic juice.) Utilization of proteids and fats remains nor- 

 mal for some time, with excessive destruction of both to com- 

 pensate for the lack of carbohydrate combustion, and a conse- 

 quent increased elimination of nitrogen in the urine. Indeed, 

 the amount of nitrogen eliminated may exceed that taken in with 

 the food, because of the wasting in the tissues. This loss is 

 commonly, although without conclusive proof, attributed to the 

 action of poisonous substances upon the tissues, and called 

 " toxogenic proteid disintegration." Associated with this tissue 

 destruction is the presence in the urine of excessive quantities 

 of purin bodies derived from the tissues (endogenous purin 

 bodies). If all carbohydrates are eliminated from the diet, 

 excretion of sugar may continue, indicating that sugar may be 

 formed from proteids and fats. According to v. Noorden, syn- 

 thesis of fat from carbohydrates is also impaired in most cases 

 of diabetes, leading to wasting ; but in some cases the synthesis 

 of fat is not impaired, and in this event the fat tissues, being 

 richly bathed with carbohydrates, build up excessive quantities 

 of fat, leading to obesity. At first this formation of fat from 

 the sugar may prevent glycosuria, but later the glycosuria 

 appears, and we have the common form of " diabetes in the 

 obese." l 



Loss of sugar and its consequences are not the only abnor- 

 malities from which diabetics suffer. The excessive quantity of 



1 According to Thoinotand Delamare (Presse He'd., 1904 (12), 491), pancre- 

 atic lesions are not present in cases of diabetes in the obese nor in nervous 

 diabetes. 



