OXYGEN RESPIRATION 2$ 



Of the usual explanations of toxic action the following are 

 worthy of note. 



Palladin^ assumed that under the influence of poisons there 

 was a large production of respiratory enzymes within the poi- 

 soned cells. According to Palladin this is a common effect 

 from weak poisoning. It is estabHshed that enzymatic oxida- 

 tion and fermentation processes cannot be increased by alka- 

 loids and other stimulants outside of cells. At present the 

 formation of an enzyme outside of living protoplasm is also 

 unknown. 



Warburg has expressed his belief^ that boundary surface 

 phenomena play an important role in the respiratory process. 

 Many poisons are strongly surface active and for that reason 

 interfere violently in the respiratory process. Both theories 

 are really valuable as working hypotheses. 



It w^ill be demonstrated later on that most of the processes 

 which take place in respiration also persist outside of living 

 cells, if the protoplasm is killed in such a way that most of its 

 enzymes of fermentation and oxidation are not destroyed. 

 It happens that many poisons which act injuriously on the 

 living protoplasm (toluol, ether and others), only slightly 

 influence the activity of the enzymes. Such substances are 

 called protoplasmic poisons.^ Other poisons are about as 

 toxic to the protoplasm as to the enzymes isolated therefrom. 

 These are the so-called enzyme poisons. They include corro- 

 sive sublimate, sodium fluoride and similar poisons. Above 

 all it is certainly very important to clarify the mechanism of 

 enzyme poisons. ^ 



Chemically indifferent substances can also produce noticeable 

 stimulating effects under certain conditions. Thus Zaleski'* 

 has shown that the respiratory intensity of bulbs of Gladiolus 



1 Palladin, W. Jahrb. f. wiss. Bot. 47: 431. 1910. 



2 Warburg, O. Zeitschr. f. Elektroehem. 28: 70. 1922. [Idem. Science 61:575-582, 

 1925; Biochem. Z. 119: 134. 1921.] 



' Palladin, W. /ot. cj7.; Euler, H. v. und af Ugglas. Z. f. physiol. Chem. 70: 279. jgii. 



* Zaleski, W. Zur Frage der Einwirkung von Reizstoffen auf die Pflanzenatmung. 1907. 

 Russian. 



" From discussions which follow it will be evident that the toxic effect of KCN 

 is probably due to its relation to the iron content of both enzymes and living 

 cells. — Ed. 



