662 DIABETES 



glyceric aldehyde, is chiefly converted into glucose before further util- 

 ization, and that this process is carried out mainly in the liver and 

 bowel wall. The literature of the subject is given below. ^^ 



LEVULOSE (FRUCTOSE) 



The group of eight sugars formed by levulose in the presence of 

 alkali includes glucose, and any member of this group will produce 

 all the others. Then, in cases of glycosuria with alkaline urine 

 (whether physiological or due to medication or to bacterial decompo- 

 sition), levulose might be expected to occur along with glucose. ^lay 

 and Koenigsfeld have reported instances of this "urinogenous levu- 

 losuria." Magnus-Levy doubts the correctness of these observations. 



Alimentary Levulosuria. — The tolerance of a normal body for levu- 

 lose given per os is variable. Doses of 50 to 70 gm. in man cause as a 

 rule no levulosuria, but more is likely to do so. Animals in which 

 the liver parenchyma has been damaged by phosphorus are said to 

 have a lower tolerance. In many other diseases of the liver the same 

 holds true, and H. Strauss believed this fact could be made the basis 

 of a clinical test for liver function. Naunyn, however, emphasizes 

 the fact that in certain cases of cirrhosis of the liver with collateral 

 anastomoses between the portal vein and vena cava, there is also a 

 lessened tolerance for levulose given by mouth, owing to the fact that 

 levulose then enters the general circulation without having entered 

 the liver. As far back as 1871 Eichhorst showed that levulose intro- 

 duced per rectum, i. e., where it will presumably enter an hemor- 

 rhoidal vein after resorption, is more likely to cause alimentary 

 levulosuria than when swallowed, because of the extra-hepatic an- 

 astomoses between the hemorrhoidal veins and the vena cava. As in 

 the case of diose, glyceric aldehyde and galactose, intravenous injection 

 of levulose produces levulosuria in dogs when the rate of injection is 

 between 0.1 and 0.2 gram per kilo per hour. These facts support the 

 belief that the liver plays the same important part in "assimilating" 

 levulose as with other sugars. 



Spontaneous Alwientary Levulosuria, i. e., the appearance of lev- 

 ulose in the urine from such small quantities of levulose as occur 

 naturally in the food, has been demonstrated in eight cases. In five 

 of these levulose appears to have been the only sugar present. These 

 persons showed a decreased tolerance for ingested levulose and ceased 

 passing the sugar when the diet was carbohydrate-free. The tend- 

 ency of thought would be to look for the cause of such phenomena 

 in a disturbed hepatic function. 



" Bauer, Deut. med. Woch., 1908 (35), 1505; Reiss u. Jehn. Deut. Arch. f. 

 Min. Med., 1912 (108), 187; Roubitscheck, Deut. Arch. f. klin. Med., 1912 (108), 

 225; Naunyn, "Beitrage zur Lehre von Ikterus, etc.," Reichcrt-Dubrissches 

 Archiv. ftir Anatomic, 1869, p. 579; Schopffer, Arch. f. exp. Path. u. Phamo., 1873 

 (1), 73. 



