60 Chapter 111 



action of the three pancreatic ferments. The duodenal juice of the 

 dog, especially, contains enterokynase. When this juice is mixed with 

 a pancreatic juice that by itself actively digests fibrin and albumen, 

 digestion takes place still more rapidly, the action being from three 

 to four times as great. The part played by the intestinal juice 

 becomes even more evident when it is mixed with a pancreatic juice 

 that has little or almost no activity, as is the case of that from dogs 

 that have recently been operated upon. Thus pancreatic juice, which 

 has no action upon albumen, digests it promptly when a certain 

 quantity of duodenal juice is added. When Che*powalmkoff took 

 500 c.c. of inactive pancreatic juice diluted with 500 c.c. of water 

 or soda solution and added to it but a single drop of intestinal juice, 

 the mixture exerted a manifest digestive action on coagulated 

 albumen. 



If, in place of pancreatic juice, we take the aqueous or glycerinated 

 extract of the pancreas, which by itself exerts a very insignificant 

 digestive action on albumen, and add to it intestinal juice, digestion 

 takes place immediately. If it be admitted, as several physiologists 

 maintain, that the inactivity of the pancreas is due to the fact that we 

 have zymogen present in place of trypsin, one might conclude with 

 Chepowalnikoff that "the intestinal juice possesses the power of 

 transforming the zymogen into trypsin, and that this transformation 

 takes place in a much more marked degree than in the presence 

 of acids or the oxygen of the air" (p. 137). 



The intestinal juice, from whatever region of the small intestine it 

 be derived, exercises an undoubtedly favourable influence on the 

 digestion of starch by the pancreatic juice, but this action is much 

 more feeble than that on trypsin digestion. The action of the 

 intestinal juice on the saponification of fats is even less marked. 

 But here it is to the bile that the more important rdle is transferred. 

 This fluid also augments the activity of the pancreatic juice, but 

 in a manner different from the intestinal juice, for it acts especially 

 by accelerating the digestion of fatty substances. 



[65] The action on the pancreatic digestion is not in any way interfered 

 with when the bile is heated to boiling point. On the other hand 

 the intestinal juice, under these conditions, completely loses its 

 accelerating role. It follows from this, as has been formulated by 

 Pawloff, that, in the intestinal juice, the existence of a soluble ferment 

 which is destroyed by heat must be admitted; to this ferment he 

 proposes to give the name of enterokynase. Without exercising 



