COUPLING OF REDUCED PYRIDINE NUCLEOTIDE OXIDATION 



173 



TABLE III 



Effect of Various Quinones on the Mitochondrial Oxidation of 

 extraahtochondrial tpxh in the presence of dt diaphorase 



Additions 



Relative oxygen consumption 



vitamin K3 (2-methyl-i,4-naphtho- 



quinone) 

 1 ,2-naphthoquinone 

 1 ,4-naphthoquinone 

 2-hydroxy- 1 ,4-naphthoquinone 

 2-methyl-3 -hydroxy- 1,4- 



naphthoquinone 



/)-benzoquinone 

 2-methylbenzoquinone 

 2,6-dimethylbenzoquinone 

 coenz\TTie Qo (2-methyl-5,6- 

 dimethoxybenzoquinone) 



100 

 17 

 14 

 14 



24 



15 

 10 



9 

 14 

 13 



Conditions as in Fig. 2. The amount of quinone was 10 - /L^mole added in 

 10 /d. ethanol. Respiration of the system with vitamin K3 was 5 "20 ^atoms oxygen/ 

 20 min. [Cono\er and Ernster, unpublished]. 



^ 100 



2 3 A 



Amytal ( M xlO^ ) 



Fig. 3. EflFect of Amytal on the respiration of liver slices. Each Warburg 

 vessel contained 50 /^moles glucose, 200 mg. rat liver slices and 2-0 ml. Krebs- 

 ringer-phosphate solution (pH 7-4). Gas phase, oxygen. Temperature, 37 . 

 Time measured, 60 min. [7]. 



