388 THE LIVER. 



Where does the sugar eliminated in diabetes originate? Does it 

 depend entirely upon the carbohydrates of the food or the store of car- 

 bohydrate in the body, or has the body the power of producing sugar 

 from other material? To LUTHJE belongs the credit for positively 

 deciding this question. He has made experiments on dogs with pancreas 

 diabetes, in which on a protein diet free from carbohydrates so much 

 sugar was eliminated that it could not possibly be accounted for by the 

 store of glycogen or other carbohydrate-containing substances in the body. 

 Similar experiments were also performed later by PFLUGER, 1 'with the 

 results that the power of the animal body to produce sugar from non- 

 carbohydrate material is now definitely proven. 



Is this sugar produced from protein or fat, or from both? This ques- 

 tion so far has not been answered, and it is the subject of continuous 

 dispute. It is not possible to enter into an exhaustive and detailed 

 discussion of the question in a text-book, and we will only mention, 

 briefly, certain of the most important observations and historical points. 



The largest amount of sugar which we can obtain theoretically from 

 protein is 8 grams of sugar from 1 gram of protein nitrogen if we admit 

 that all the carbon of the protein, with the exception of that necessary 

 to form ammonium carbonate, is used for the formation of sugar. These 

 results are still somewhat too high for the average carbon and nitrogen 

 content of the proteins and the values D : N = 6.6 is probably more correct. 2 

 The actual relation between dextrose and nitrogen in the urine, i.e., 

 the quotient D:N, has been repeatedly determined in various forms of 

 diabetes, and in depancreatized dogs it is generally 2.8 and in starving 

 dogs or dogs fed with protein and poisoned with phlorhizin it is equal to 

 3.65 (LUSK). It may undergo considerable variation, and in certain cases 

 it may indeed be lower than 1 as well as higher than 8, and high results 

 have been repeatedly obtained in cases of human diabetes. From these 

 quotients conclusions have been drawn as to the amount of sugar formed, 

 as well as the origin of the sugar, but according to the views of HAMMARS- 

 TEN such conclusions are mostly very uncertain. The sugar eliminated 

 by the urine represents the difference between the total sugar produc- 

 tion of the body and the quantity of sugar burned or utilized. Only 

 under the supposition that the body cannot burn or utilize any sugar 

 is the sugar of the urine a measure of the quantity of sugar produced: 

 it is not known how far this supposition can be applied in the various 

 forms of diabetes. Still several observations seem to show that in the 

 different forms of diabetes variable amounts of the sugar are burned, 



l Luthje, Deutsch. Arch. f. klin. Med., 79, and Pfliiger's Arch., 106; Pfliiger, 

 Pfluger's Arch., 108. 



2 See Falta, Zeitschr. f. klin. Med., 65. 



