THE OXIDIZING ENZYMES 81 



or in diabetes, or when the liver undergoes self-digestion, which 

 speaks against Spitzer's contention that oxidase is a nucleopro- 

 teid. 1 Schlesinger 2 found that it is less in amount in livers of 

 children dead from gastro-intestinal diseases than in normal 

 livers, as also did Briining. 3 I am inclined to believe that fatty 

 metamorphosis, when brought about by poisons, is often due to 

 inhibition of the oxidizing enzymes (v. fatty metamorphosis). 

 Buxton 4 failed to find in tumors any enzyme giving the guaiac 

 test alone, but found enzymes that did so in the presence of 

 H 2 O 2 (peroxidases). Catalase was present, but no very positive 

 reactions for oxidizing enzymes were obtained by the indo-phenol 

 reaction, the hydrochinon reaction, or with tyrosin for tyrosinase. 



Meyer 5 found that leucocytes, whether from pus or leukemic 

 or pneumonic blood, contained a substance oxidizing guaiac 

 directly, without the presence of H 2 O 2 , which is not liberated 

 until the cells are destroyed. The observation of Natalie 

 Sieber 6 that oxidases of the blood and of vegetable origin 

 destroy diphtheria toxin rapidly, and also tetanus toxin and 

 ricin, has been confirmed by Loewenstein as far as destruction 

 by peroxide, with or without the presence of catalase, is con- 

 cerned. Oxidation is undoubtedly an important process in 

 defending the body against other forms of poisons. (See " De- 

 fense of the Body against' Poisons of Known Composition.") 

 Schmidt 7 has found that by oxidation certain poisonous mor- 

 phin derivatives are rendered non-poisonous by liver extracts. 

 Oxalic acid and other poisonous fatty acids are also oxidized 

 into harmless substances ; phosphorus and sulphur are oxidized 

 into their acids, which are then neutralized. Indol and skatol 

 are oxidized into less harmful substances. 



Glycolytic Enzymes. 8 The oxidation of sugar by the 

 tissues, which is one of the chief sources of energy in the ani- 

 mal body, presumably takes place through several steps. Of 

 these, it is believed by some that the first is the formation of 

 glycuronic acid 



//Q //V> 



CH 2 OH (CHOH) 4 C H + O 2 = COOH-(CHOH) 4 C H + H 2 O, 

 (glucose) (glycuronic acid) 



1 Duccheschi and Almagia (Arch. ital. Biol., 1903 (39), 29) also found the 

 aldehydase in livers of phosphorus poisoning usually no less abundant than in 

 normal livers. 



2 Hofmeister's Beitr., 1903 (4), 87. 



3 Monat. f.' Kinderheilk., 1903 (2), 129. 



4 Jour. Med. Kesearch, 1903 (9), 356. 



5 Munch, med. Woch., 1903 (50). 1489. 



6 Zeit. physiol. Chem., 1901 (32), 573. 



7 Dissertation, Heidelberg, 1901. 



8 Also discussed under " Diabetes," chap. xxii. 



