ON PANCREATIC PROTEOLYSIS. 213 



addition of normal bile are in themselves sufficient to account 

 for the retardation noticed. Similarly, such stimulation of 

 proteolysis as results may be due as much to a more favorable 

 change in the reaction of the mixture as to any other cause. 



IV. INFLUENCE OF BILE SALTS ON THE PROTEOLYTIC 

 ACTION OF THE PANCREATIC ENZYME IN NEUTRAL 

 AND ALKALINE SOLUTION. 



In considering the action of the salts of the bile acids on 

 pancreatic proteolysis it is to be remembered that in ox bile 

 both glycocholate and taurocholate of sodium are present, 

 although the proportion of the two acids is subject to consid- 

 erable variation. In most cases, when ox bile is acidified, the 

 proportion of taurocholic acid present is sufficient to hold the 

 less soluble glycocholic acid in solution, but in some cases 

 the latter predominates to such an extent that it will crystallize 

 out under the above conditions. Thus Marshall * found as 

 the result of an examination of 543 samples of bile from as 

 many oxen that a separation of glycocholic acid could be 

 obtained in only 121 cases, i. e., in 22.2 per cent. This fact is 

 worthy of note in the present connection as illustrating not 

 only the variable composition of bile from a given species, but 

 also as an indication of the variability of composition to be 

 expected in the preparation of " crystallized bile." f Further, 

 in pig's bile we have to do mainly with the sodium salts of 

 two special forms of glycocholic acid known as a- and y8- 

 hyo-glycocholic acid.J In the preparation of crystallized bile, 

 i. e., the sodium salts of the above acids, the ordinary methods 

 of procedure were followed, and need not be detailed here. 



Following are the results obtained in studying the influence 

 of these preparations on pancreatic proteolysis under the 

 conditions specified : 



* Marshall, J., Zeitschr. f. physiol. Chemie, 1887, ii, p. 233. 



t For the variation in the proportion of glycocholate and taurocholate 

 present in human bile see the results reported by Hammarsten : Zur Kenntniss 

 der Lebergalle des Menschen. Mitgetheilt der konigl. Gescllsch. d. Wissen- 

 schaf ten zu Upsala, 16 Juni, 1893. Separatabzug. 



i Jolin, S., Zeitschr. f. physiol. Chemie, 1888, xii, p. 512, and xiii, p. 205. 



