EXPERIMENTAL DIABETES 351 



of what has been liberated from proteid in the organism. 

 Minkowski, to answer this question, fed depancreated dogs with 

 different amounts of dextrose, and estimated how much of this 

 reappeared in the urine. He concluded from his results that 

 when moderate amounts of dextrose are ingested it all re- 

 appears in the urine. 1 



It should, however, be pointed out that in the dogs to which 

 dextrose was given the nitrogenous excretion was usually distinctly 

 below its previous level, which would tend to indicate, either a 

 proteid- sparing action of the dextrose presumably, therefore, 

 its partial oxidation or, that the absorbed dextrose in such cases 

 never really enters the tissue cells, but, by still further raising 

 the percentage of sugar in the blood, tends to prevent diffusion 

 of the sugar, which the cells themselves produce from proteid, 

 into the blood to tend, as it were, to overcrowd the cells with 

 sugar produced by their own metabolism and hence to lessen 

 the activity of their proteid break-down. An explanation along 

 this line is offered by M. Cremer. By some such process all the 

 administered dextrose would reappear in the urine without its 

 coming into actual contact with the tissue cells. 



It is generally concluded by other workers, however, that a 

 small proportion of the dextrose-destroying power of the organism 

 still remains in depancreated dogs, i.e. that all the administered 

 dextrose does not reappear in the urine, although the greater part 

 of it does. This being so, it would appear probable that sugar 

 of proteid origin would behave similarly. Why, then, is a D : N 

 ratio of about 7 not obtained ? The only answer possible is 

 that all the carbon of proteid is not available to form sugar 

 (as is assumed in the above calculation), but only a portion 

 of it. 



How do other carbohydrates behave ^vhen given with the 

 food ? 



Starch is very imperfectly digested in the absence of the 

 pancreatic juice, so that a large proportion of it reappears un- 

 changed in the faeces, and, of what does not thus reappear, 

 much becomes destroyed in the. intestines by putrefactive 



1 When large amounts were given, intestinal disturbance (diarrhoea, &c.) 

 occurred, and when small amounts were given it was difficult to measure the 

 increase on account of the normal variations in the sugar excretion in de- 

 pancreated dogs. 



