[Reprinted from the Journal of Physiology. 

 Vol. XXXIII. No. 6, February 5, 1906.] 



ON THE MECHANISM OF PROTECTION OF INTES- 

 TINAL WORMS, AND ITS BEARING ON THE 

 RELATION OF ENTEROKINASE TO TRYPSIN. BY 

 J. MOLYNEUXHAMILL, M.A., M.B. (Cantab.), B.Sc. (Land.), 



Sharpey Scholar. 



(From the Physiological Laboratory of University College, 



London.) 



THE discovery of antiferrnents naturally suggested that the resistance 

 of intestinal parasites to digestion might be due to the presence of an 

 antiferraent in their tissues. This view has been advocated by 

 Weinland (2) , who considers that the resistance of intestinal parasites to 

 digestion is due to the presence of antiferments, especially anti- trypsin, 

 in their tissues. On the other hand, Dastre and Stassano (3) , who 

 have investigated the nature of the antibody in Ascaris, have come to 

 the conclusion that it is not anti-tryptic but anti-kinasic in action. In 

 dealing with these different results, it is necessary to take into account 

 the different views which are held as to the interaction of enterokinase 

 and trypsinogen. 



According to Pawlow, enterokinase acts as an enzyme, converting 

 trypsinogen into trypsin in the same way that trypsin converts proteids 

 into simpler products. Delezenne (1) , however, assigns quite a different 

 role to enterokinase; according to him the conversion of trypsinogen 

 into trypsin is brought about by a combination of the enterokinase with 

 the trypsinogen, the resulting complex being trypsin. He endeavours 

 to bring the activation of trypsinogen by enterokinase into line with 

 the interaction between complement and immune-body. He regards 

 enterokinase as a complement, and trypsinogen as an immune-body, 

 either of these substances alone is unable to attack proteid, but when 

 all three, enterokinase, trypsinogen, and proteid are brought together, 

 the trypsinogen, acting as an amboceptor, allows the enterokinase to 

 attack and break up the proteid molecule. 



PH. xxxni. 32 



