OXALATE BINDING TO RAT-KIDNEY MITOCHONDRIA - INDUCTION BY OXIDIZED GLUTATHIONE

Increased oxalate binding with negative correlation with reduced gluta thione content was observed during lipid peroxidation in rat kidney mi tochondria. In presence of oxidized glutathione (GSSG), peroxidized mi tochondria lost 48% of protein-SH with concomitant 3-fold increase in oxalate binding activity while control mitochondria lost only 20% prot ein-SH with only 0.8 fold increase in oxalate binding activity. The GS SG-induced oxalate binding was apparently due to two-fold increased af finity of oxalate to the protein. Reduced glutathione (GSH) inhibited oxalate binding competitively with K-i, 1.4x10(-3) M. Urolithic rat ki dney mitochondria showed 30-50% increase in oxalate binding activity a long with depletion of GSH and protein-SH. These studies suggest that oxalate binding is regulated by thiol status of mitochondria.