CH. XXXIII.] DIABETES 517 



process the sugar or its derivative glycuronic acid is split into 

 smaller molecules and ultimately into water and carbon dioxide. 

 The close relationship of sugar and glycuronic acid is shown 

 by the following formulae: 



COH COH 



(CHOH) 4 (CHOH) 4 



CH 2 OH > COOH 



[Dextrose.] [Glycuronic acid.] 



That is two hydrogen atoms in the CH. 2 OH group are replaced by 

 one of oxygen. This oxidation is readily brought about in the body, 

 and glycuronic acid is usually found in diabetic urine; but the 

 further oxidation into water and carbon dioxide is a more difficult 

 task, because it involves the disruption of the linkage of the carbon 

 atoms. Perhaps it is here that the internal secretion of the pancreas 

 is effective. This, however, is at present a mere theory, and certainly 

 Lepine's idea that the ferment of the pancreatic internal secretion is 

 one which initiates glycolysis or sugar-splitting in the Uood, has been 

 abundantly disproved. It may be that the active principle of the 

 pancreatic internal secretion stimulates the glycolytic action of the 

 tissue-cells. It is conceivable that in the other great cause of 

 glycosuria, namely, injury to nervous structures, as in Bernard's 

 puncture experiment, the derangement of the nervous system 

 exerts some unknown influence on the pancreas as well as on the 

 liver. 



(3) By administration of phloridzin. Many poisons produce 

 temporary glycosuria, but the most interesting and powerful of these 

 is phloridzin. The diabetes produced is very intense. Phloridzin is 

 a glucoside, but the sugar passed in the urine is too great to be 

 accounted for by the small amount of sugar derivable from the drug. 

 Besides that, phloretin, a derivative of phloridzin, free from sugar, 

 produces the same results. 



Phloridzin produces diabetes in starved animals, or in those in 

 which any carbohydrate store must have been got rid of by the 

 previous administration of the same drug. Phloridzin-diabetes is 

 therefore analogous to those intense forms of diabetes in man in which 

 the sugar must be derived from protoplasmic metabolism. 



A puzzling feature is the absence of an increase of sugar in the blood ; if the 

 phloridzin is directly injected into one renal artery, sugar rapidly appears in the 

 secretion of that kidney ; the sugar is formed within the kidney cells from some 

 substance in the blood, but whether that substance is proteid or not is uncertain. 

 The action of the kidney cells in forming sugar has been compared to that of the 

 mammary cells in forming lactose. 



Acetonaemia. Death in diabetic patients is usually preceded by 

 deep coma, or unconsciousness. Some poison must be produced that 

 acts soporifically upon the brain. The breath and urine of these 



