GLYCOSURIAS. 401 



circulating in the blood, perhaps from a protein with loosely combined 

 carbohydrate groups. 



GRUBE from experiments upon the surviving tortoise liver has made the 

 suggestion that it is not the kidneys which are first attacked by the phlorhizin 

 action in phlorhizin glycosuria but the liver. Important experimental evidence 

 against this view has been raised by SCHONDORFF and SucKROW. 1 



Another form of glycosuria which according to certain investigators 

 is to be connected with a changed permeability of the kidneys (UNDER- 

 BILL and CLOSSON) is the glycosuria first observed by BOCK and HOFF- 

 MANN after the intravascular injection of large quantities of a 1-per 

 cent salt solution, which is also of great interest because, as shown by 

 MARTIN FiscHER, 2 it can be again arrested by an injection of a salt solu- 

 tion containing CaC^. There are investigators who attempt to connect 

 this glycosuria with the adrenals and a hyperglyca3mia. 



With the exception of these two forms of glycosuria, the phlorhizin 

 diabetes and the salt-glycosuria, and also the glycosuria produced by 

 certain kidney poisons, all other forms of glycosuria or diabetes, as far 

 as known at present, depend on a hyperglyccemia. 



A hyperglyca3mia may be caused in various ways. It may be caused, 

 for example, by the introduction of more sugar than the body can destroy. 



The ability of the animal body to assimilate the different varieties 

 of sugar has naturally a limit. If too much sugar is introduced into the 

 intestinal tract at one time, so that the so-called assimilation limit 

 (see Chapter VIII, on absorption) is overreached, then the excess of 

 absorbed sugar passes into the urine. This form of glycosuria is called 

 alimentary glycosuria, 3 and is caused by the passage of more sugar into 

 the blood than the liver and other organs can destroy. 



As the liver cannot transform into glycogen all the sugar which comes 

 to it in these, to a certain extent physiological, alimentary glycosurias, 

 it is possible that a glycosuria may also be produced under pathological 

 conditions, even by a moderate amount of carbohydrate (100 grams 

 glucose), which a healthy person could overcome. This is true, among 

 other cases, in various affections of the cerebral system and in certain 

 chronic poisonings. Certain observers include the lighter forms of 



1 Grube, Pfliiger's Arch., 128; Schondorff and Suckrow, ibid., 138. See also the 

 opposed view of Underbill, Journ. of biol. Chem., 13. 



2 Bock and Hoffmann, Arch. f. (Anat. u.) Physiol., 1871; M. Fischer, University 

 of California publications Physiol., 1903 and 1904, and Pfluger's Arch., 106 and 109; 

 Underbill and Closson, Amer. Journ. of Physiol., 15, and Journ. of Biol. Chem., 4. 



3 In regard to alimentary glycosuria see Moritz, Arch. f. klin. Med., 46, which also 

 contains the earlier literature; B. Rosenberg, Ueber das Vorkommen der alimentaren 

 Glykosurie, etc. (Inaug.-Dissert. Berlin, 1897); van Oondt, Munch, med. Wochen- 

 schr., 1898; v. Noorden, Die Zuckerkrankheit, 3. Aufl., 1901. 



