ACTIVATION OF THE PANCREATIC JUICE. 473 



assumption. According to FROUIN l the influence of the various foods 

 consists in that the latter give to the juice a different activation. Accord- 

 ing to FROUIN, for the activation to maximum amount of trypsin the 

 meat juice requires 1/500-1/1000 of its volume of intestinal juice, and 

 bread -juice 1/20-1/10 of its volume. The question as to the influence 

 of the food upon the properties of the juice is still unsettled and requires 

 further study. 



If we accept the view that the juice secreted after partaking food 

 is regularly free from trypsin, still under other circumstances the juice 

 may contain trypsin. Thus according to CAMUS and GLEY the juice 

 secreted under the influence of secretin (see below) is not always free from 

 trypsin, and ZUNZ found that WITTE'S peptone or pilocarpine causes a 

 secretion of juice which often contained trypsin and was directly active. 

 According to CAMUS and GLEY not only does an exterior activation of the 

 trypsinogen in the juice take place, but also in the interior of the gland. 

 An auto-activation of the juice in certain cases is also accepted by others 

 (SAWITSCH 2 ) . 



The activation of the trypsinogen into trypsin may, in life, be brought about 

 .as the researches of HERZEN, which have been substantiated by GACHET and 

 PACHON, BELLAMY, MENDEL and RETTGER, have shown not only in the intestine, 

 but also in the gland itself. This activation of the trypsinogen in the gland itself 

 is caused in a still undiscovered manner by a body of unknown nature formed in the 

 spleen, which is congested during digestion. Such a " charging " of the pancreas 

 by the spleen has been repeatedly suggested by ScniFF, 3 but this has recently 

 been denied by PRYM. According to this experimenter the extirpation of the 

 spleen causes no change in the properties of the pancreatic juice, and the intra- 

 venous injection of spleen infusion is also without action on a splenectomized 

 dog with permanent pancreatic fistula. The observations of HERZEN that a 

 spleen infusion has a strong activating action upon a weak pancreas infusion 

 were substantiated by PRYM/ but he claims that this is due essentially to micro- 

 organisms. 



The formation of lactase after the introduction of milk sugar into the intestine 

 as observed by WEINLAND and BAINBRIDGE, is to be considered as an intraglandular 

 enzyme formation in the pancreas. This is a special example of the general 

 rule based upon BROCARD'S researches, that the kind of food has a marked influence 

 upon the formation of hydrolytic ferments in the body: " c'est I'aihueiit qui fait 

 le ferment." This formation of lactase is denied by others such as BIERRY and 



PLIMMER. 5 



1 Compt. rend. soc. biol., 63. 



2 Camus and Gley, Journ. de Physiol. et de Pathol. gen., 1907; Zunz, Recherches 

 sur 1'activation de sac pancreatique par les Sels., Bruxelles, 1907; Sawitsch, Zentralbl. 

 f. d. ges. Physiol. u. Path, des Stoffwechsels, 1909. 



3 Bellamy, Journ. of Physiol.. 27; Mendel and Rettger, Amer. Journ. of Physiol., 7. 

 A very complete reference to the literature may be found in Menia Besbokaia Du 

 rapport fonctionell entre le pankre"as et la rate, Lausanne, 1901. 



4 Pfliiger's Arch., 104 and 107. 



5 Weinland, Zeitschr. f. Biologic, 38 and 40; Brocard, Journ. de physiol. et de 

 path. ge"n., 4; Bainbridge, Journ. of Physiol., 31. Contradictory views are held 



