72 ENZYMES 



enzyme, causing violent local hemorrhagic inflammation. Schep- 

 ilewsky 1 also found papain much more toxic than rennin and 

 pancreatin; repeated injection of the two latter caused amyloid- 

 osis in rabbits. Lombroso 2 found that inactive pancreatic juice 

 was much less toxic than the activated, showing that it is 

 the trypsin that is the important toxic agent. He also found 

 that succus entericus in doses of 1 to 5 c.c. is toxic, but not 

 lethal for dogs. Hildebrandt 3 observed that enzymes were 

 positively chemotactic, but it is probable that the products of 

 their action on the tissues are the chief chemotactic agents. 



The enzymes that are secreted into the gastro-intestinal tract 

 seem to be chiefly destroyed, but part is eliminated in the feces, 

 and part that is absorbed apparently reappears in the urine in 

 very small quantities. Pepsin, diastase, and rennin all have 

 been found in normal urine ; but the occurrence of trypsin is 

 unsettled. Zeri 4 could find no lipase in normal or nephritic 

 urine, except when blood or leucocytes were present. Fer- 

 ments injected stibcutaneously seem seldom to be eliminated in 

 any considerable amounts in the urine, but Opie 5 has demon- 

 strated the presence of lipase in the urine in pancreatitis with 

 fat necrosis. Hildebrandt was able to prove that emulsin 

 remained active for at least six hours a^'ter it was injected 

 into animals subcutaneously, by its splitting amygdalin which 

 was then injected, the CNH liberated by the cleavage of the 

 amygdalin causing death. 



Anti-enzymes. Injection of enzymes into animals leads to 

 the appearance of substances in the serum of the animals that 

 antagonize the action of the enzymes. The principles involved 

 are quite the same as in the immunization of animals against 

 bacterial toxins or against foreign proteids. This seems to have 

 been first observed by Hildebraudt, and it has been taken up 

 extensively in recent years in the study of the problems of 

 immunity. An interesting observation that was made rather 

 early in these studies was that normal blood-serum possesses a 

 marked resistance against the action of proteolytic enzymes, not 

 being at all digested by dilutions of enzymes that will rapidly 

 digest a serum that has been heated This property seems to be 

 shared by egg-white and by the tissues and organs of the body 

 (Levene and Stookey 6 ). The anti-enzyme action seems to be 



1 Cent. f. Bakt., 1899 (25), 849. 

 Abstract in Biochem. Centralblatt, 1903 (1), 712. 

 Virchow's Arch., 1893 (131), 5. 

 II Policlinico, 1905 (12), 733. 

 Johns Hopkins Hosp. Bull., 1902 (13), 117. 

 Jour. Medical Research, 1903 (10), 217. 



