66 ENZYMES 



the increased aiititryptic activity results from the formation of 

 specific antibodies for the intracellular proteases liberated during the 

 disease, but as yet this has not been satisfactorily established, so we 

 do not know whether the "antitrypsin reaction" depends upon an 

 antibody for trypsin or upon some entirely different factor. In 

 cachexia the inhibiting effect of the serum is especialh' marked and 

 it is therefore usually pronounced in cancer, but the increased inhibi- 

 tion is sometimes absent in cancer (10 per cent, of all cases) and often 

 present in other conditions, so that the positive diagnostic value is 

 slight. It may also be present without cachexia and often seems to 

 parallel the number of leucocytes in the circulating blood. Sarcoma 

 shows it less than carcinoma, while in exophthalmic goitre and tuber- 

 culosis an antitryptic increase is said to be quite constant (Waelli).*"^ 

 As normal serum contains a tryptic enzyme as well as a substance 

 inhibiting trypsin, the antitryptic activity is at most but a measure of 

 the difference between these (Weil), and might depend on either 

 lowered trypsin or increased antitrypsin content. Doblin *'^ and many 

 others believe with Jobling that the active agent is not a true immune 

 antibody, but as yet general agreement has not been reached on this 

 point (see Meyer). Kirchheim ^^'^ has found that the union of trypsin 

 and antitrypsin does not follow the physico-chemical laws of a true 

 antigen-antibody reaction. Rosenthal has advanced evidence to sup- 

 port the hypothesis that the presence of products of protein cleavage 

 in the serum is responsible for the antitryptic action, but this has not 

 been confirmed. Attempts have been made to regulate suppurative 

 processes by the introduction of either leucocytic proteases, or anti- 

 protease in the form of active serum (see Wiens •'''''). Whether anti- 

 protease can be specifically developed by immunizing with leuco- 

 protease is a matter of disagreement,**- but no increase of antiprotease 

 follows the enormous destruction of leucocytes caused by injecting 

 tliorium-A'."-' 



The anti-enzymatic property obtained in the serum by injecting 

 enzymes into animals differs from that normally present in the senim 

 in many ways. It may be made much stronger than it ever is in 

 normal serum, and against many varieties of enzymes for which an 

 anti-enz.yme docs not naturally exist. Especially important is the 

 fact that it is highly specific (v. Eisler) ; serum of an animal immu- 

 nized against dog trypsin will show a much greater effect against dog 

 trypsin than it does against tryi)sin from other animals. This fact 

 permits us to distinguisli between enzymes of ap]iarently similar na- 

 ture but of different origin, and ])roves that they have a structure at 



60 Mitt. Crenz. Mod. u. Cliir.. 1912 (25), 1S4. 

 11 Zeit. f. Iminunitiit, 1009 (4), 229. 

 Ola Arch. oxp. Patli.. 191.3 (7.3), 1.39. 

 «2 See Bradley, Jour, llyg., 1910 (12), 209. 

 03 G. Rosenow and Fiirb'er, Zcit. cxp. Mod., 1914 (3), 377. 



