ANTIFERMENTS 249 



After he had proved experimentally that the animal organism is able 

 to defend itself against foreign substances by mobilization of ferments, 

 Abderhalden next took up the question whether protective ferments are 

 produced when substances native to the body but foreign to the blood are 

 introduced into the circulation. Having learned from the researches 

 of Veit, Schmorl, Weichard, and others, that during pregnancy syncytial 

 cells frequently enter the maternal circulation, Abderhalden used the 

 serums of pregnant animals, and found that they contained a ferment 

 capable of splitting placental peptone into amino-acids and coagulated 

 placenta into peptones, polypeptids, and amino-acids. 



It was thus established that the body-cells are harmonically attuned 

 to one another, and if new or modified cells or their products are brought 

 into relation with other cells, they are received as foreign invaders, and 

 their entrance is followed by the production of protective ferments 

 ("Abwehrfermente") capable of bringing about their cleavage into 

 simpler products. In this manner the presence in the circulation of some 

 of the body-cells may give rise to the production of these ferments if the 

 cells in question are really foreign to the blood-plasma and other cells. 



Abderhalden is careful to note that although he was led to make 

 these investigations on the supposition that syncytial elements were 

 present in the blood of pregnant women, it is not necessary that they be 

 constantly in the blood, for every case of pregnancy has a complicated 

 protein metabolism and there is a general exchange of substances between 

 the placenta and the maternal blood that permits the entrance into the 

 latter of protein products that have not been broken down completely 

 into amino-acids, and that cause the organism to produce defensive 

 proteolytic ferments. 



In cancer, where the production of new cells is so marked, some of 

 these cells or their products may easily be swept into the general circula- 

 tion, where they act as foreign invaders and cause the formation of pro- 

 tective proteolytic ferments. It is a noteworthy fact, moreover,, that 

 the serum of carcinoma cases reacts best with carcinoma cells and that 

 of sarcoma with sarcoma cells. 



Similar ferments have been described in other conditions. Fauser 

 has demonstrated that the blood-serum of dementia prsecox patients 

 contains ferments that act on the reproduction glands, so that the serum 

 of males reacts with testicular extracts and that of females with ovarian 

 extracts. These serums were, however, also found to react with thyroid 

 tissue and brain cortex. In general paresis reactions were obtained with 

 brain cortex and liver, also at times with thyroid gland, reproductive 

 glands, and more rarely with kidney. 



