ON PANCREATIC PROTEOLYSIS. 203 



Experiment 17. Human bile.* Neutral extract of ox pancreas. 



Per cent of Bile. Undigested Residue. Fibrin Digested. Relative Proteolytic Action. 







1.0 



2.0 



3.0 



6.0 



10.0 



20.0 



40.0 



In looking through these various experiments it is manifest 

 that the addition of fresh bile to a neutral pancreatic extract 

 does not give rise to any very great degree of stimulation, i. e., 

 the proteid-digesting power of the enzyme is not markedly 

 increased. Calling the digestive power of the control mixture 

 without bile 100, it is rare to find the digestive power of the 

 enzyme raised above 108 by addition of bile. Increased 

 proteolysis, however, is certainly induced many times by the 

 addition of bile, and it is somewhat noticeable that this increase 

 is obtained more frequently in the presence of large per- 

 centages 10-25 per cent than in the presence of smaller 

 amounts. Still, in no one of our experiments do we find a 

 confirmation of the results reported by Rachford and South- 

 gate, who found on an average " that the proteolytic action of 

 pancreatic juice on neutral fibrin was increased one-fourth by 

 the addition of bile." Further, it is noticeable in our experi- 

 ments that in fully 50 per cent of the results inhibition of 

 proteolysis is produced, although here, likewise, the retarding 

 effect is not very marked. Rarely does the relative proteolytic 

 action fall below 90. Our results, therefore, seemingly justify 

 the statement that the addition of bile to a neutral solution of 

 the pancreatic enzyme, even to the extent of 25 per cent, does 

 not materially modify its proteolytic power; stimulation or 

 inhibition may result, but not, under ordinary circumstances, 

 to any very great degree. Still, the question arises at once 

 why we have both stimulation and retardation. Obviously, 



* Containing 17.96 per cent of solid matter. 



