ASCORBATE-INDUCED LYSIS OF ISOLATED jMITOCHONDKIA 67 



An important question not fully answered is whether ascorbate causes 

 rupture of the membrane at one or at many points. The latter appears to 

 be more likely, for many submitochondrial particles of small size are 

 formed. Since ascorbate lysis occurs after swelling induced by phosphate 

 and other agents has stopped, when the membrane permeability has 

 greatly increased and sucrose has probably come to equilibrium internally 



Ascorbate +^ /A 



t 

 Cyto. A + Aj CN, azide 



added cyto. C 



Cyto.C 



t 

 Cyto.C, 



..A Antimycin A 



7 ' SN 5949 



Ascorbate ■ »- Cyto. B or UQ 



Flavin Flavin 



Malonate ]-•- ---T Amytal 



Succinate DPN 



t 

 /3-OH-Butyrate 



Fig. 20. Possible interrelationships between swelling inducing agents, in- 

 hibitors, and the electron transport chain. 



and externally, the ascorbate effect would seem to involve rupture of 

 links in the membrane structure and not further osmotic swelling. The 

 action of ascorbate may give clues to key groups or links in the membrane 

 structure. It seems unlikely that this effect is related to the vitamin role 

 of ascorbate, but this cannot be ruled out completely. 



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