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Scientific Proceedings (8i). 



a starch-splitting enzyme. There is also abundant evidence that 

 the term amylase is applied to a variety of starch-splitting enzymes 

 characterized chiefly by the extent of the hydrolysis, such as the 

 production of soluble starch, dextrins, and reducing sugars. We 

 have found that the blood of a given animal may vary consider- 

 ably from day to day, sometimes producing dextrins slowly and 

 reducing sugars rapidly, or dextrins rapidly and reducing sugars 

 slowly. It is evident that the study of the formation of a pro- 

 tective amylase after parenteral introduction of starch calls for a 

 quantitative study of at least three phases of starch hydrolysis. 



We have at hand data on seven dogs. These animals have 

 received both single and repeated intravenous injections of soluble 

 starch. No constant or significant increase in the amylolytic 

 activity of the blood has been found. There is, however, a great 

 increase in the amylolytic power of the urine on the day following 

 the injection of the starch, the increase being shown by a more 

 rapid production of both dextrins and of reducing sugars. 



In the interpretation of these results it appears possible that 

 there is an increased production of amylase after the injection of 

 starch, but the kidneys eliminate it so rapidly that there never is 

 present in the blood enough of the excess over the normal to be 

 detected by any of our present methods. On the other hand the 

 amylase may be present in the blood in an inactive state, perhaps 

 in combination with some colloid, and on the introduction of a 

 suitable substrate this combination is broken up, and at least a 

 part of the enzyme eliminated by the kidneys before it can re- 

 combine. 



Experiments are now in progress for the purpose of determining 

 whether there is an actual increased production, and if so, where it 

 takes place, and also to throw more light on the second hypothesis 

 mentioned above. 



