Studies on so-called protective ferments. IV. The Abderhalden test is rendered negative by the addition of serumantitrypsin

Abstract

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 reëstablished 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 saponified 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 of serum globulin seems to promote the appearance of dialyzable substances, probably on account of the digestion of the globulin by the serum ferment.