SERUM ENZYMES 527 



activity was discovered. In consequence there has been a tendency 

 to draw a fundamental physiological distinction between these types 

 of cells, a distinction which would have considerable importance 

 in discussions of their origin and significance. 



Jochmann has an idea that the activities of these ferments in 

 connection with tissue destruction and other pathological conditions 

 where they become active, may be an important phase in the produc- 

 tion of fever. 



An important question which immediately arises is whether these 

 ferments can be identified with the bactericidal substances described 

 in a preceding chapter as existing within leucocytes. According to 

 Jochmann the enzyme extracts have no bactericidal properties. In- 

 deed, it is a curious fact that living bacteria oppose a very powerful 

 resistance to digestion by these and other ferments. Kantorowicz, 8 

 who has studied this particularly, has shown that living bacteria 

 contain a very powerful antiferment which is similar to the anti- 

 ferment presently to be described for blood serum. He has shown 

 that living bacteria cannot be digested by trypsin, a resistance which 

 is lost when the bacteria are heated to 80 C., and an extract of 

 living bacteria will prevent the tryptic digestion of the heated bac- 

 teria. It will appear, therefore, that in the process of phagocytosis 

 the bacteria are first killed by the bactericidal substances contained 

 in the cells and are later digested by the leucoprotease. 



That the lymphocytes contain lipase has been mentioned above 

 and since these cells are specifically accumulated about tuberculous 

 foci it has been many times suggested that their function is particu- 

 larly directed against these acid-fast bacteria in whose constitution 

 the presence of waxes and fats plays such an important role. It is 

 a fascinating thought, though entirely conjectural, that perhaps the 

 specific benefit of feeding fats in tuberculosis may have some basis in 

 the possible increase of lipolytic ferments which appear in response 

 to the stimulation of introducing larger quantities of fats. 



It is hardly necessary to reiterate here the possible importance 

 of these cellular enzymes in the many different phases of the ab- 

 sorption of larval organs which occurs in the lower animals in the 

 course of normal development, or of dead tissue in mammalia in 

 disease and in the processes of senescence. 



In addition to proteolytic enzymes, it has been long known that 

 the leucocytes also contain an oxidase. This enzyme can be demon- 

 strated by the well-known guaiac test, in which tincture of guaiac is 

 added to leucocytic exudates or pus, and a blue color results as a 

 consequence of oxidation of the guaiac. The oxidizing ferment is 

 apparently limited to the polynuclear leucocytes. Exactly what its 

 significance is we do not know but it is highly probable that it plays 

 an important part in the intracellular metabolism of the leucocyte. 



8 Kantorowicz. Munch, med. Woch., p. 897, Vol. 56, 1909. 



