A\Ti-E\zy.][i:s 63 



mal urine; but trypsin is present chiefly as trypsinogen, especially 

 abundant after a meat diet.''- Pepsin and rennin enter the urine as 

 the zymogens, in quantities in proportion to the amount in the 

 stomach, and are absent in gastric carcinoma (Puld and Hirayama^^). 

 During resolution of pneumonia, leucocytic protease may appear in 

 the urine (Bittorf ^*). Ferments injected subcutaneously seem sel- 

 dom to be eliminated in any considerable amounts in the urine, but 

 Opie ^^ has demonstrated the presence of lipase in the urine in pan- 

 creatitis with fat necrosis. Hildebrandt was able to prove that emulsin 

 remained active for at least six houi's after it was injected into animals 

 subcutaneous!}', 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 sub- 

 stances in the senim 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 

 proteins. This seems to have been first observed by Hildebrandt, 

 and it has been taken up extensively in recent years in the stud}' 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^^). The anti-enzyme action is easily destroyed, by heat of 

 about 70°, by the action of dilute acids, and even by prolonged stand- 

 ing. It is exerted not only against the secreted ^proteolytic enzjones, 

 pepsin and trypsin, but also against the intracellular enzymes of 

 various organs. 



It seems highly probable that the resistajice of the body tissues to 

 digestion by their own enzymes and by the enzymes of one another 

 depends in some way upon the presence of anti-enzymes in the cells 

 ;ind tissue fluids, for self -digestion of tissues is greatly impeded by 

 serum.^^ Weiland^*' has demonstrated that certain intestinal worms 



32 V. Schoenborn. Zeit. f. Biol.. 1010 (53), 386. 



33Berl. klin. Woch., 1010 (47), 1062. 



3* Dent. Arch. klin. :\led.. 1007 (91), 212. 



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



37 According to Porter (Quart. .Joxir. Exper. Physiol., 1910 (3), 37o) enzymes 

 in contact with various membranes are inactivated, and substances appear which 

 are strongly inhibitivo to the enzymes: it is possible that this effect depends 

 largely on zvmoids, which unite with the substrate and deviate the enzymes. 



37aSugimoto. Arch. exp. Path.. 1013 (74), 14. 



38 Jour. Medical Pesearch. 1003 (10), 217. 



39 Wells, Jour. Med. Pesearch, lOOG (10). 149. 



•to Zeit. f. Biol.. 1003 (44), 45: see also Dastre and Stassano. Compt. Pend. 

 Soc. Biol., 1003 (55), 130 and 254: and TTamill, Jour, of Physiol., 1906 (33), 470. 



