Studies on So-Called Protective Ferments. 



55 



have shown that the mechanism of the formation of toxin is that 

 of autodigestion of the serum with the formation of toxic split 

 products. 4 This autodigestion is made possible through the 

 liberation of non-specific proteolytic enzyme normally present in 

 the blood of every animal. 5 These results seem to suggest another 

 theory of the causation of eclampsia. 



The development of the ovum is accompanied by metabolic 

 changes in the body directly connected with the requirements of 

 this new growth. In addition, the penetration into the general 

 circulation of detached cells of the developing embryo together 

 with the metabolic products of the growing fetus, sets up a new 

 specific process of parenteral digestion of these substances in the 

 body of the mother. As the gestation progresses and the products 

 of the new growth repeatedly penetrate the general circulation 

 they cause the appearance of specific antibodies of a cytolytic 

 nature. My experiments suggest that such antibodies by com- 

 bining with the antigen change the balance of the blood constitu- 

 ents so as to allow the liberation of the serum trypsin, which 

 in turn digests the antigen circulating in the blood. 6 This 

 trypsin, however, is capable of digesting also the serum itself. 

 The products of such autodigestion of serum are very toxic and 

 when they occur in early pregnancy they may induce symptoms 

 of nausea, dizziness, general depression and so forth. If the 

 amount of toxin produced by this autodigestion of serum goes 

 beyond the limit of tolerance for the individual, acute symptoms 

 of anaphylaxis result and we witness the eclamptic convulsions. 



Normally the intoxication from the split products of such 

 autodigestion is prevented by at least two independent processes. 

 One is the overproduction of antitrypsin, which prevents the 

 excessive autodigestion of serum by neutralizing the proteolytic 

 ferments; the other is the elimination of toxic substances through 

 the liver and kidneys which retain these toxins and, therefore, 

 show signs of local involvement long before the general symptoms 

 are noticed. That the antitrypsin of the blood is involved in this 

 process was shown in this laboratory by the actual measurements 7 



* Bronfenbrenner, Proc. Soc. Exp. Biol, and Med., 1914, XII, p. 7. 

 6 Bronfenbrenner, Journ. Exp. Med., 1915, XXI, p. 221. 



( Bronfenbrenner and Scott, Proc. Soc. Exp. Biol, and Med., 1915, XII, p. 137. 

 ' Full records of these experiments will be published in the near future. 



