ARTICLES 425 



an enzyme which accelerated the oxidation of the phenols. In 

 support of its being a true enzyme, he found that it was 

 destroyed by boiling, was inhibited by acids and rendered 

 more active by alkalies. 



Catalase. — Of recent years much attention has been given 

 to the study of catalase, an enzyme which is capable of decom- 

 posing hydrogen peroxide with the evolution of molecular 

 oxygen as a gas, but which does not cause oxidation as the oxygen 

 evolved is inactive. 



According to Bach (19 13) it plays an important role in pro- 

 tecting sensitive parts of the cell mechanism from the action 

 of easily diffusible hydrogen peroxide found in the oxidation 

 processes. Bach also states that in a mixture of hydrogen 

 peroxide with both catalase and peroxidase, the peroxide is 

 decomposed partly into active oxygen, and partly into mole- 

 cular oxygen, according to the relative amount of the two 

 enzymes present. It would appear, therefore, that catalase 

 may act as a regulator of the oxidation process. Here it 

 may be noted that the earlier observer, Loew, found the 

 catalase from tobacco leaves and from the poppy seed were able 

 to oxidise hydroquinone to quinine, but gave no other oxidase 

 reactions. 



Other than Bach, no author is apparently willing to commit 

 himself in any further speculation as to the function of catalase. 

 There is, however, increasing evidence as to its importance, 

 since it is so closely related in its distribution and amount to 

 certain activities of the body : indeed it seems very probable 

 that it will be proved to be one of the most important factors 

 in the body mechanism. 



It has been stated by Vernon that starvation of rats or 

 frogs did not influence the amount of catalase found in the 

 tissues, although Jolles and Oppenheim found that the cata- 

 lytic power of human blood decreased in certain diseases, e.g. 

 carcinoma, tuberculosis and nephritis. In 191 7 the work of 

 Burge and Neill did not confirm that of Vernon, but tended to 

 substantiate that of Jolles and Oppenheim. Burge and Neill 

 found that during starvation catalase was much decreased in 

 the voluntary muscles and adipose tissue (except the heart 

 muscle, where the amount was normal). And it is suggested 

 that the decrease of catalase in these tissues leaves the auto- 

 lytic enzymes free to digest them. 



On the same lines is the conclusion of Megath (191 7) regard- 

 ing the protection of intestinal worms. He found that there 

 were considerable amounts of catalase in the body-wall of 

 intestinal worms, and concluded that the worms were protected 

 from the intestinal enzymes by nascent oxygen produced by the 

 catalase. This gives support to the theory originally put for- 



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