EXPERIMENTAL DIABETES 347 



Pancreatic Diabetes. On 22nd May 1889 von Mering and 

 Minkowski l made the announcement that total extirpation of the 

 pancreas in dogs was followed by severe diabetes, which persisted 

 until the death of the animal. Previous to this, pathologists had 

 noticed that in severe forms of Diabetes mellitus in man morbid 

 changes in the pancreas were not uncommon. 



In a later publication, in 1893, Minkowski ( 19 ) gives in detail 

 a description of the operation for the excision of the gland, and an 

 account of his investigation on dogs and other animals thus 

 rendered diabetic. Briefly, the most important of these results 

 are as follows. 



Total extirpation of the pancreas is followed by diabetes in 

 dogs, cats, pigs, and frogs; if any trace of pancreatic tissue be 

 left, however, no glycosuria, or only a mild form of it, results. 2 

 Extirpation of any other gland or organ than the pancreas does 

 not produce diabetes, although the operative interference may 

 cause temporary glycosuria. 



In rabbits, total extirpation of the gland is technically im- 

 possible on account of the glandular tissue being spread out 

 diffusely between the layers of the mesentery. In herbivorous 

 birds glycosuria only occasionally follows pancreatic extirpation, 

 whereas in carnivorous birds it always occurs. 



The most important observations have been made on dogs. A 

 few hours after the extirpation, in these animals, sugar appears in 

 the urine. In twenty- four hours this usually attains a percentage 

 of about one, and it markedly increases during the second day 

 (3-4 per cent.), to attain on the third day a maximum percentage 

 of from 8-10, after which, if no food be given, a gradual 

 fall occurs. If, instead of merely ascertaining the percentage, the 

 total sugar excretion of twenty- four hours be estimated, it will be 

 found that during starvation, after the preliminary rise described 

 above, a constant level is attained, and, if the amount of dextrose 

 excretion be compared with that of nitrogen in other words, if 

 the ratio of dextrose to nitrogen D : N be determined a constant 



1 Dominicis almost simultaneously made the same discovery. 



2 In this connection it is interesting to note that where the whole gland has 

 been successfully removed the abdominal wound, despite all surgical care, 

 suppurates, and if it heals at all, does so only by second intention, whereas, if 

 some of the gland be left, and no diabetes, or only a mild form of it be thus 

 established, primary union is more likely to follow. The diabetic state so lessens 

 the resistance of the tissues that infection readily occurs. 



