GLYCOSUlilA 043 



whicli leads to the excretion of acetone, accto-acotic acid and ^-liy- 

 droxybutyric acid in the urine, the reader is refernMl to the section 

 on acidosis. (Chapter xx). 



Whereas the normal urine at all times contains reducing substances 

 and substances which are optically active, which yield crystalline 

 compounds with the hydrazines and respond to other so-called sugar 

 tests, these substances are not all sugars, nor are all the sugars glucose. 

 The quantity of fermentable reducing substance in normal urine 

 averages about 4 parts in 10,000 (0.04 per cent.) acording to Lavesson.^ 

 If the total quantity of urine were 1500 c.c. this would imply a daily 

 excretion of about 0.6 gm. Bang and Bohmannson' estimated the 

 total reducing substance in the urine of normal adults as between 

 0.21 and 0.24 per cent., of which about 18 per cent, was fermentable 

 (0.038 to 0.043 per cent, of fermentable reducing substances in the 

 urine). This is doutbless subject to change depending on the diet 

 and other factors. Benedict, Osterberg and Neuwirth'* found an 

 excretion of fermentable reducing substance ranging between 0.903 

 and 1.161 gm. in twenty-four hours in the case of a normal adult on 

 an ordinary mixed diet. During a fast it fell to zero, according to 

 these writers, and on a diet low in carbohj-'drate it averaged 0.75 gm. 

 while with a high carbohj^drate diet it rose to 1.5 gm. 



When an abnormal amount of sugar occurs in the urine, regardless 

 of the kind, the condition may be called, in accordance with Naunyn's 

 suggestion, melituria. When the sugar is glucose (dextrose), the 

 term glycosuria is applied; when levulose, levulosiiria , and so on. 

 Other known forms of melituria are lactosuria, galactosuria, fructo- 

 suria, pentosuria, etc. All these are but symptoms, manj' of them 

 being caused by a variety of mechanisms, which will be discussed 

 presently. 



The term diabetes is often loosely used to cover any variety of 

 melituria, but is is preferably limited to certain forms; namely, to 

 the glycosurias (or the mixed meliturias in wliich d-glucose is the 

 predominating sugar), and further than this, to those particular 

 glycosurias which continue even after the glycogen reserves of the 

 body have become depleted and when the diet is free of carbohydrate; 

 or, to those transient glycosurias whose nature by one means or another 

 can be proved to be identical with the continuous forms (latent or 

 mild diabetes). Over against these are the meliturias in which other 

 sugars than glucose play the chief role, and glycosiirias which are essen- 

 tially transient because they depend solely on the ingestion or admin- 

 istration of excessive quantities of glucose or the sudden liberation 

 into the blood of glucose derived from preformed glycogen or other 

 fixed compound of sugar. 



2 Biochem. Zeit., 1907 (4). 40. 



3 Zeit. physiol. Chem., 1909 (63), 443. 

 * Jour. Biol. Chem., 1918 (34), 217. 



