ASCORBATE-INDUCED LYSIS OF ISOLATED MITOCHONDRIA 



6i 



Because the experimental data could suggest an ascorbate-metal 

 catalyzed oxidative change in some labile key group in the membrane, 

 possibly not really involving the electron transport chain, we investigated 



0.5 



0.4 



ImM HpOp REPEATED 

 ■ ^ * i 



30 40 



MINUTES 



Fig. II. Failure of addtd H.^Oj, H.,Oo-forming enzyme systems, or catalase 

 to modify significantly ascorbate-induced lysis of mitochondria. 



20 30 



MINUTES 



40 



50 



60 



Fig. 12. Comparison of the absorbancy changes due to ascorbate lysis of 

 mitochondria with those produced by lipoate and reagents which react with thiol 

 and dithiol groups. 



additional sulphvdrvl compounds and reagents which react with thiol and 

 dithiol groups. The swelling inducing effect of arsenite [i] and p-ch\or- 

 mercuribenzoate have been reported [lo]. Carefully investigated over a 

 wide range of concentrations, none of these compounds produced a 

 typical ascorbate-like effect (Fig. 12). Oxidized lipoic acid, arsenite, and 



