54 



F. EDMUND HUNTER, JR. 



values, much lower than the plateau seen with phosphate and substrates. 

 An important characteristic is that ascorbate lysis occurs only with low 

 concentrations, o-2-i mM being optimal. Higher concentrations lengthen 



0,5 



0.4 



0,3 



0.2 



0.1 



CONTROL 



- • -■-♦— * " --a . 



•^ 



ASCORBATE 

 5mM 

 ^. lOmM 



i 

 5m M PO4 



2mM^-0H-BUTYRATE \ 



A 



0.2- ImM ASCORBATE ^ 



20 30 40 



MINUTES 



50 



60 



Fig. I. Absorbancy changes at 520 m/it when dilute suspensions of liver 

 mitochondria are treated with phosphate, /3-hydroxybutyrate, or ascorbate. All 

 additions made at zero time. Mitochondrial protein was 150 /^g./ml. 



0.5 



0.4 



o 0.3 

 in 



0.2 - 



0.1 - 



10 



20 



30 40 



Ml NUTES 



50 



60 



Fig. 2. Absorbancy changes due to swelling or lysis of mitochondria induced 

 by cysteine or glutathione. 



the lag period and inhibit swelling, until 15 mM prevents swelling com- 

 pletely for I to 2 hr. This has special significance, for high concentrations 

 of ascorbate do not block phosphate or substrate-induced swelling. 



Figure 2 demonstrates that reduced glutathione (GSH) and cysteine 

 produce an absorbancy change like that seen with low concentrations of 



