58 F. EDMUND HUNTER, JR. 



just as they do other swelhng agents. Possibly they should be grouped with 

 EDTA. As has been observed in other work Mn + + is considerably more 

 effective than Mg + + in preserving mitochondrial structure. Because of 



0.5 



20 30 40 



MINUTES 



Fig. 6. Inhibition of ascorbate-induced lysis of mitochondria by metal com- 

 plexing agents. 



0.5 



0.4- 



0.3 



o 



CO 

 ID 

 < 



0.2 - 



0.1 - 



10 



20 



30 40 



MINUTES 



50 



60 



Fig. 7. Inhibition of ascorbate-induced lysis of mitochondria by Mg + +, 

 Mn + +, pyruvate, and oxaloacetate. 



the inhibitory effect of 15 mM ascorbate, several possible reducing sub- 

 stances were tested. Two mM nitrite has only a slight effect, but 20 mM 

 frequently blocks completely for some time (Fig. 8). Hydroquinone and 

 catechol completely prevent ascorbate-induced lysis in concentrations 

 which have no effect or smaller effects on phosphate swelling. This may 



