THE SPLENO-PANCREATIC INTERNAL SECRETION. 



409 



This may be further demonstrated by showing that oxygen 

 does exist in the blood, and that if we were dealing with 

 zymogen it would be oxidized therein. The oxidation of sugar 

 converted from glycogen, we have seen, represents the main 

 factor in the production of functional energy in the muscles 

 and other structures. That sugar occurs in the blood nor- 

 mally, but in small quantities, its combustion therein depend- 

 ing mainly as in toxic glycosurias upon suprarenal activity, 

 we have also seen. The more these organs produce of their 

 secretion, the greater is the proportion of oxidizing substance 

 in the blood, and suprarenal insufficiency means a correspond- 

 ing increase of sugar in the blood through imperfect oxidation. 

 Hence the oxidizing substance is a sugar-destroying agency. 



That an agent capable of consuming sugar exists in the 

 blood was ascertained by Lepine in 1889, who named it "glyco- 

 lytic enzyme." Howell, referring to this substance, says: "It 

 has been asserted by Lepine and Barral that there is normally 

 present in the blood an enzyme capable of destroying sugar. 

 Their theory rests upon the undoubted fact that sugar added 

 to blood outside the body soon disappears" This obviously con- 

 stitutes another proof of the existence of oxidizing substance 

 in the blood. 



Howell, referring also to the supposed source of Lepine's 

 glycolytic enzyme, says, referring to the pathogenesis of glyco- 

 suria: "The most plausible theory suggested is that the inter- 

 nal secretion produced contains a special enzyme, glycolytic 

 enzyme, whose presence in the blood is necessary for the con- 

 sumption of sugar. Such an enzyme may be obtained from the 

 blood, but it is not proved whether it is a normal constituent 

 or whether it is produced after the blood is shed by the dis- 

 integration of some of its corpuscular elements." . . . "It 

 is interesting and suggestive to state, in this connection, that 

 post-mortem examination in cases of diabetes mellitus in the 

 human being has shown that this disease is associated in some 

 instances with obvious alterations in the structure of the pan- 

 creas." That the glycolytic enzyme is, as oxidizing substance, 

 a normal constituent of the blood is obvious; but the inter- 

 esting feature to determine now is whether, as believed by 

 Lepine, the pancreas is the source of the ferment, since, if it 



