I Hi mi I IB0LI8M OP Till CABBOHTDRAT] - 



a sudden instead of a very gradual increase in thi r concentration 



of the blood, the condition- being quite unlike those which exist during 

 the normal absorption of glucose Prom the intestine. The mechanism 

 by which the body ordinarily disp if excessive amounts of glue 



absorbed into the portal blood, is nol adjusted to operate when the 

 temic blood is suddenly overcharged with this Bubstance. In the 

 case the glucose is a foodstuff; in the other, because of it- ■ jive 

 concentration in the blood, it is more or less of a poison. Such results, in 

 other words, merely show us how much glucose can be add< '1 al 

 time to the organism without any overflow into the urine, but I 

 furnish us with no information regarding the power of the org m to 

 utilize a constant though moderate excess of this substance. In the 

 case it is the "saturation limit," in the other the "utilization limit" of 

 the organism for glucose, that we are really considering. 



Consideration of these principles has led Woodyatt, Sansum and Wil- 

 der 20 to undertake a thorough reinvestigation of the whole problem of 

 the utilization or, as they prefer to call it. tin toleranct <>f thi h<>(]>i for 

 (jlucose. They emphasize the obvious fad that the ability of the organism 

 to utilize glucose "must depend on the rate at which the tissues are 

 able to abstracl it from the blood by their combined powers, to burn it. 

 to reduce it into fat or to polymerize it into glycogen." To form any 

 estimate of the combined effect of these processes, we must take into 

 account not only the amount of glucose per unit of body weighl grams 

 per kilogram), but also the rate of injection, for "toll must be 



regarded as a velocity, not as a weight." 



Briefly summarized, the conclusions which Woodyatt, etc., have bo far 

 drawn from their investigations are as follows: in a normal rabbit, dog, 

 or man. 0.8 0.9 gm. of glucose per kilogram body weight and per hour 

 be utilized by the organism for an indefinite time without causing gly- 

 cosuria. When between 0.8 and 2 gm. are injected, a part of the ex 

 appeals hi the urine, steadily increasing until a maximum is read 

 after which the excreted fraction remains constant at about one-ten' 



If more than about 'J grams per kilogram an hour are injected, "a 1 

 percentage of all glucose in excess of the 2 gm. per kilogram an hour 

 appears in the urine when constant conditions are once established." 



The fact that so much glucose injected intravenously can be Ufi 

 without the appearance of any of it in the urine, indicates a method by 

 which foodstuffs may be supplied to the tissues in cases where, on account 



of gastrointestinal disturbances, it is impossible to have f 1 a! 



by the usual pathways. The possible value of such a method of tr 

 ment in cases of extreme weakness lias ben tested on laboratory animals 

 by Allen, who states that such injection seems to ha\ luable nutri- 



