GLYCOSURIAS 657 



loiiji'ed iiitravi'iioiis injections of lactose into dogs at tlie rate of 2 fjin. 

 ])er kilo j)er hour, lactose was excreted at the rate of injection diii-iiif? 

 the fourth hour and the following four hours.'" 



Leopold and Reusse reported that when 1 gram of la(;tose was 

 injected subcutaneously into a dog or infant, exactly 1 gram reap- 

 peared in the urine; but that if the injections were made daily, the 

 ([uantity excreted fell little by little and finally became zero. Ilelm- 

 liolz and Woodyatt have repeated this experiment in dogs, and found 

 that at first the gram injected might reappear in the urine as stated. 

 Sometimes, however, the occurrence of an increase in the reducing 

 power of the urine above the figure representing 1 gram of lactose 

 was noted. This suggested a splitting of the lactose into glucose 

 and galactose. Nor could they obtain more than a temporary disap- 

 pearance of the sugar following subsequent injections, even when 

 carried on for weeks — such as Leopold and Reusse reported. The 

 point of chief interest in these experiments is that the apparently in- 

 creased hydrolysis of lactose developing with successive doses resem- 

 bles a reaction of immunity, with a substance of known chemical 

 composition as the antigen. But it is possible that the successive in- 

 jections simply result in a lessened excretion of the lactose by the kid- 

 ney's. Abderhalden and his co-workers reported that the serum of 

 animals similarly treated develops an increased power to split the di- 

 saccharide employed, as determined by means of the polariscope. 

 These experiments were paralleled with cane sugar (saccharose) and 

 with di-, tri-, and higher peptids. Other observers have failed to cor- 

 roborate these findings. 



Saccharosuria (cane sugar in the urine) occurs under conditions 

 quite similar to those mentioned for lactose, except that there is no 

 saccharosuria corresponding to the lactosuria of women. 



Maltosuria has often been reported, but the chemical detection of 

 this sugar is uncertain. 



Other polysaccharoses, such as isomaltose, glycogen, etc., have been 

 thought by some writers, to occur in the urine. 



GLYCOSURIAS 



Glucose is the sugar which enters into the normal glycogen and 

 forms the bulk of the body sugar. Glycosurias are naturally the 

 most important of the meliturias. 



(1) Alimentary glycosuria, e saccharo. Not infrequently it is im- 

 possible to make a healthy man eat and retain sufficient glucose to 

 cause glycosuria, and it would be hard to define an increased glucose 

 tolerance. This statement is corroborated by the recent studies of 

 Taylor and Hutton ^■' on man. Li dogs weighing 10 kilos the maxi- 

 mum rate of glucose absorption is apparently reached with doses of 



34 Unpublished experiments hv W. D. Sansum. 



35 Jour. Biol. Cliem., lOlG (25), 173. 



42 



