AUTOLYSIS IN PATHOLOGICAL PROCESSES 89 



exudates are tliose of cancer and tuberculosis, tlie least active are 

 passive congestion fluids; pleural exudates contain more active enzymes 

 than peritoneal exudates of .similar character. 



Knapp^- holds that in pus the cocci and the enzymes they produce 

 are responsible for much of the digestion. Pus cells alone do not 

 undergo digestion so rapidly as when bacteria are present, and di- 

 gestion is more rapid if the bacteria are alive than when inhibited or 

 killed by antiseptics. Streptococcus is almost inactive, staphylococcus 

 is quite active, and B. coli still more so. However, pus corpuscles 

 free from bacteria are highly proteolytic, causing digestion in serum 

 plates in dilutions of 1-700 (Jochmann). Knapp could find no rela- 

 tion between the autolytic power of the pus and the severity of the in- 

 fection from which it resulted. A constant constituent of pus is 

 d-lactic acid, ^2 ^nd it increases during autolysis; this may well modify 

 the rate of autolysis of pus. (See also the discussion of the "Chem- 

 istry of Pus," Chap, xi.) 



Proteolytic Enzymes of the Leucocytes.^^ — By the introduction of 

 the plate method of testing the proteolytic activitj^ of leucocytes, 

 Miiller and Jochmann brought the study of this particular vital 

 activity into the range of clinical laboratories, and aroused much 

 general interest in what had previously concerned only a few pathol- 

 ogists, especially E. L. Opie. The principle is that of permitting 

 the leucocj^tes or other cells to act upon a blood serum plate at a tem- 

 perature of 55°, which prevents bacterial action but permits the pro- 

 teolytic enzymes of the cells to digest the coagulated serum, forming 

 depressions in the surface ("Dellbildung"). This proteolytic activity 

 is, of course, heterolysis rather than autolysis. Many modifica- 

 tions of this method have been introduced (such as using casein- 

 agar), but the principle involved is the same, and they are fully 

 explained and discussed in the article by Wiens. Normal blood does 

 not contain enough leucocytes to cause observable cUgestion, but my- 

 elogenous leukemia blood causes distinct chgcstion while lymphatic 

 leukemia does not, showing that it is the polynuclears and myelocytes 

 that are responsible. Other observations fasten the proteolytic activ- 

 ity upon the neutrophile granules. Leucocytes of normal human 

 blood will, if concentrated enough, cause digestion of serum plates, 

 as also, of course, will pus. The leucocytes of rabbits, guinea pigs, 

 and practically all animals except man, apes and monkej^s, are de- 

 void of proteolytic activity demonstrable by the plate method. Nor- 

 mal serum, both homologous and heterologous, exercises a strong 

 inhibition on this digestion, so that it is necessary to have an excess of 

 leucocytes present to obtain the reaction. The activity of leucocytic 

 autolysis is indicated by the observation that in drawn cerebrospinal 



12 Ito, Jour. Biol. Chem., 1916 (26), 173. 



'^ Full bibliography by Wiens, Ergebnisse Phj-siol., 1911 (15), 1; Jochmann, 

 Kolle and Wassermann's Handbuch, 1912 (2), 1301. 



