SECRETION OF PANCREATIC JUICE. 499 



secretin, which according to BAYLISS and STARLING/ is the same in all 

 vertebrates examined, is not destroyed by heat; it is therefore not 

 identical with etiterokinase, and is not considered an enzyme. It is 

 formed from another substance, prosecretin, by the action of acids. 

 According to DELEZENNE and POZERSKI secretin occurs as such in the 

 intestinal mucosa, and the acids act only by the elimination of certain 

 bodies having a retarding action. According to POPIELSKI secretin 

 action is different from acid action; and the secretin action can also be 

 obtained by WITTE'S peptone. He believes that the secretin is not 

 a specific constituent of the intestine but a body widely distributed. 

 GIZELT disputes the occurrence of a specific secretin and he compares 

 this body to peptone. GLEY has obtained a solution which had a stronger 

 secreting action than secretin by macerating the mucosa with proteoses. 2 

 v. FURTH and SCHWARZ S also call attention to the uncertainty of our 

 knowledge as to the nature of secretin. According to them secretin 

 is probably a mixture of bodies, among which probably the choline, found 

 by them in the intestinal walls, acts the role of an exciter of secretion. 



A second means of causing secretion is the fat, which probably only 

 acts after it has been saponified. Oil-soap directly introduced into the 

 duodenum brings about a strong secretion of pancreatic juice (SAWITSCH, 

 BABKiN 4 ), and at the same time a flow of bile, gastric juice, and the 

 secretion of BRUNNER'S glands occurs. The pancreatic juice secreted 

 under these circumstances has about the same amount of enzymes as 

 the juice secreted after partaking of food. 



We know very little as to how the soaps act. FLEIG 5 found that by macera- 

 tion of the mucosa of the upper part of the duodenum with soap solution, a sub- 

 stance goes into solution which he calls sapoknnin, and which when introduced 

 into the blood brings about a strong secretion of pancreatic juice. This sapok- 

 rinin, which is derived from a prosapokrinin. is not an enzyme and is not identical 

 with secretin. After the action of chloral hydrate an abundant secretion occurs 

 in the duodenum (WERTHEIMER and LEPAGE), which FALLOISE considers as pro- 

 duced by a special secretin, chloral secretin. The secretion of pancreatic juice 

 can also be increased by alcohol, and FLEIG 6 claims to have obtained a secretin, 

 ethyl secretin, by macerating the intestinal mucosa with alcohol. Further investiga- 

 tions are necessary of all these so-called secretins. 



1 Journ. of Physiol., 29. 



2 Delezenne and Pozerski, Compt. rend. soc. biol., 56; Popielski, , Centralbl. f. 

 Physiol., 19; Pfliiger's Arch. 128; Gizelt, Pfliiger's Arch. 123; Gley, Compt. Rend. 151, 

 345. 



3 v. Fiirth and Schwarz, Pfliiger's Arch. 124 (literature on secretin). 



4 Arch des scienc. biol. de St. Petersboiirg, 11, and Zeitschr. f. physiol. Chem., 56. 

 6 Compt. rend. soc. biol., 55, and Joufn. de Physiol, et de Pathol. gen., 1904. 



6 Wertheimer and Lepage, Compt. rend. soc. biol., 52; Fleig, ibid., 55; Falloise, 

 Bull. Acad. Roy. Belg., 1903. 



