PANCREATIC JUICE 251 



4. PANCREATIC JUICE 



Pancreatic juice presents different properties according as it is obtained 

 from a long-established fistula or a recent one (page 243). In the latter case 

 it is viscid or almost ropy, and at a low temperature passes over into a trans- 

 parent jelly from which a thin fluid separates out. At C. there is formed 

 a gelatinous, flocculent precipitate, readily soluble in dilute acids. Under 

 some circumstances the secretion is so rich in proteid that the whole fluid 

 coagulates when heated. The secretion from a permanent fistula is thinner 

 and contains a smaller quantity of solids. 



According to Pawlow the latter is to be regarded as the normal secretion. 

 In his experience the thick, sirupy secretion is due to the effects of the opera- 

 tion on this uncommonly sensitive gland. 



The quantity of pancreatic juice secreted daily is no more to be estimated 

 with exactness than is the quantity of gastric juice. In cases of pancreatic 

 fistula in man a daily secretion of from 293 to 840 c.c., with an average of 

 something more than 400 c.c., has been observed. 



Pancreatic juice is always alkaline in reaction and often contains an 

 abundance of proteid as the following analyses show: 



Kudrewetsky has found that the alkalinity as determined by the quantity of 

 IIC1 in g. necessary to neutralize 100 c.c. of dog's pancreatic juice is 0.05-0.89. 



Its most important constituents are the enzymes : two or three amylolytic, 

 one proteolytic and one lipolytic. Probably all of these occur in the gland 

 as zymogens. That they are actually different enzymes probably follows from 

 the fact that the amylolytic, proteolytic and lipolytic effects either of the 

 secretion or of the pancreatic extract do not keep pace one with another. 



A. THE AMYLOLYTIC ENZYMES 



Valentin (1844), also Bouchardat and Sandras (1846) found that pan- 

 creatic secretion transforms starch into sugar. The very same cleavages appear 

 in this as in the action of ptyalin on starch. Besides, pancreatic juice contains 

 an enzyme (maltase) which changes maltose to dextrose (Rohmann) and 

 according to Weinland, another (lactose) which splits milk sugar into dex- 

 trose and galactose. 



Glaessner was unable to demonstrate any action of human pancreatic juice 

 on cane sugar, maltose or milk sugar. 



The action of the amylolytic enzyme is favored by small quantities of hydro- 

 chloric acid and of bile (Rachford). 



