232 GLYCOGEN 



similation limit of the various sugars has attained consider- 

 able importance from studies which have been conducted in 

 F. Hofmeister's laboratory. 33 Using the same rabbit in a 

 series of injections of varying dosage of sugar into the 

 auricular vein one may determine the dose which the animal 

 can take without glycosuria ensuing in the course of a few 

 minutes. This amount, determined by F. Blumenthal as 1.8 

 to 2.8 grams for a rabbit, proved repeatedly for the individ- 

 ual animal remarkably constant (within 0.1 gram). These 

 figures, an expression of the ability of the body to take up the 

 sugar and its conversion products from the circulation to a 

 point of saturation, is known as the ' l saturation limit. ' ' It 

 furnishes a useful means of measuring the actual appropri- 

 ating power of the body for any given time. It is not quite 

 the same thing as the "utilization limit," which is de- 

 termined by finding out by intermittent, graded sugar injec- 

 tions the largest amount which can be borne continuously 

 when introduced regularly at short intervals without ensuing 

 glycosuria. Apparently when the saturation limit has been 

 once reached by a large administration of sugar, a very 

 small continued additional amount is sufficient to maintain a 

 glycosuria. 



It may be readily seen that an alimentary glycosuria 38a 

 is more likely to occur in an individual whose glycogen de- 

 posits are excessive from previous indulgence in carbo- 

 hydrate food, than in one poor in glycogen; and that 

 muscular labor 34 and over exposure to heat, 35 by increasing 

 the requirement of sugar, raise the limit of assimilation. A 

 number of other agencies which are apt to modify the 

 assimilation limit will be taken up later. 



88 F. Blumenthal (F. Hofmeister's Lab., Strassburg), Hofmeister's Beitr., 

 6, 329, 1905. 



M a Literature upon Alimentary Glycosuria: A. Magnus-Levy, Handb. d. 

 Biochem., 4', 323-327, 1909. 



**G. Comessati (F. Hofmeister's Lab., Strassburg), Hofmeister's Beitr., 

 9, 66, 1907; Grober (Stintzing Clinic, Jena), Deutsch. Arch. f. klin. Med., 95, 

 137, 1909. 



85 H. Hohlweg and F. Voit (Giessen), Zeitschr. f. Biol., 51, 491, 1908. 



