6 



Scientific Proceedings (6i). 



4 (936) 



Studies on so-called protective ferments. IV. The Abderhalden 

 test is rendered negative by the addition of serum- 

 anti trypsin. 



By J. Bronfenbrenner. 



[From the Pathological and Research Laboratories of the Western 

 Pennsylvania Hospital, Pittsburgh, Pa.] 



The view which regards blood serum as a digestive fluid is not 

 a new one, and the importance of the mechanism regulating the 

 activity of the ferments of the blood while in the body has recently 

 been clearly detailed by Dr. Victor C. Vaughan. 1 The study of 

 these ferments was lately taken up by Jobling and Petersen 2 who 

 showed that the non-saturated fatty acids of the serum are in a 

 way responsible for the inactivity of the proteolytic enzymes in 

 the blood. 



The experiments have shown that — as I expected — serum 

 extracted with chloroform gives up dialyzable substances reacting 

 with Ninhydrin; I further ascertained that the addition of non- 

 saturated fatty acids in form of soap or in form of large excess of 

 normal serum reestablished the antitryptic properties of the 

 treated serum, thus stopping the appearance of dialyzable protein 

 substances. I then tried to see if the same procedure would 

 also stop the auto-digestion of the serum exposed to its own 

 ferments through the action of kaolin or starch on the one hand, 

 and of the antigen-antibody combination on the other. The 

 experiments confirmed the expectations in every case completely, 

 and I am therefore in a position to say that by the addition of the 

 excess of whole normal serum as well as by the addition of saponi- 

 fied fatty acids of the serum, the Abderhalden reaction is invariably 

 rendered negative, evidently through the arresting of the self- 

 digestion of the serum. 



The study of this question is not completed as yet, but even 

 now it is possible to say that not only fatty acids, but also the 

 serum-albumin tends to retard auto-digestion, while the addition 



ijour. A. M. A. 1914, Vol. 63, p. 365. 

 2 Jour, of Exp. Med., Vol, 19, 1914, p. 239. 



