Microsomal glutathione-dependent protection against lipid peroxidation acts through a factor other than glutathione peroxidase and glutathione S-transferase in rat liver.
Ascorbate-Fe3+-induced and NADPH-induced lipid peroxidation of rat liver microsomes were inhibited by glutathione (GSH). This inhibition was due to microsomal GSH-dependent factor. This factor was heat labile, and storage of microsomes at 4 degrees C for 1 week diminished the activity. GSH could not be substituted by other sulfhydryl compounds tested. Deoxycholate (1 mM) and bromosulfophthalein (0.1 mM) inhibited GSH-dependent protection but did not inhibit microsomal GSH peroxidase activity. Iodoacetate (10 mM) inhibited GSH-dependent protection but did not inhibit microsomal GSH S-transferase. N-Ethylmaleimide (0.1 mM) and oxidized glutathione (10 mM) inhibited GSH-dependent protection but activated microsomal GSH S-transferase activity. These results indicate the existence of a heat-labile, microsomal GSH-dependent protective factor against lipid peroxidation that acts through a factor other than GSH-peroxidase and GSH S-transferase.
Third Department of Internal Medicine, Yamaguchi University, School of Medicine, Japan.
Y
Y
Nagasaka
S
S
Fujii
T
T
Kaneko
D000818:Animals; D005978:Glutathione / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000494:pharmacology
D013438:Sulfhydryl Compounds; D005979:Glutathione Peroxidase; D005982:Glutathione Transferase; D005978:Glutathione