Studies on so-called protective ferments. II. Proteolytic enzyme is not specific

Abstract

If the serum of a pregnant woman is placed in a dialyzing thimble together with placenta in all respects as for an Abderhalden test, only at a temperature of 0° C., dialysis does not take place. Both the serum and placenta however undergo certain changes. Such a serum, when separated from the placenta and placed in the dialyzing thimble with fresh placenta, can no more induce any specific changes in placenta. And the placenta once placed in contact with a positive serum on ice and then separated from it, although it is not able to give up dialyzable substances by itself (if suspended in salt solution), acquires the property to do so in presence of any positive or negative, male or female fresh serum. The placenta was evidently “sensitized” and the serum exhausted of the specific substances present in pregnant serum. Moreover such a serum deprived of its specific properties still retains the ability of causing the appearance of dialyzable substances in presence of the sensitized placenta. Evidently we have here complete parallelism between this phenomenon and that of sensitization of erythrocytes by an active hemolytic serum.

In studying the complement activity of a pregnant individual's serum exhausted of its specific elements by the above method, it was found that the complement tends to deteriorate very rapidly, much more rapidly than in the male serum treated in an exactly similar way. Parallel with the deterioration of the complement and in the inverse proportion, the amount of the dialyzable protein fraction increases. The analysis of this phenomenon which will be described in detail elsewhere, led to the conclusion that the serum of a pregnant woman, treated in the way described above, acquires the ability of digesting itself.