REDUCTION OF LINOLENIC ACID HYDROPEROXIDE BY A GLUTATHIONE PEROXIDASE

1. 1. It has been shown that the reduction of linolenic acid hydroperoxide and of linoleic acid hydroperoxide by GSH is catalysed at approximately the same rate by a glutathione peroxidase in rat liver. 2. 2. The products formed by the enzymatic reduction of linolenic acid hydroperoxide have been identified as 9-hydroxy-10,12,15-octadecatrienoic acid, 12-hydroxy-9,13,15-octadecatrienoic acid, 13-hydroxy-9,11,15-octadecatrienoic acid, 16-hydroxy-9,12,14-octadecatrienoic acid and probably 8-hydroxy-9,12,15-octadecatrienoic acid. 3. 3. Since the glutathione peroxidase seems to accept both five isomeric linolenic acid hydroperoxides and two isomeric linoleic acid hydroperoxides as substrates, it is probable that it can catalyse the reduction of the hydroperoxides of all the polyunsaturated fatty acids that occur in subcellular membranes. © 1969.