Subcellular distribution of the cytochrome P-450 complex and glutathione peroxidase activity in vitamin E and essential fatty acid deficiency

Glutathione peroxidase (EC 1.11.1.9) (GSHPx) and P-450 activity were measured in hepatic mitochondrial and microsomal fractions from rats deficient in vitamin E and/or essential fatty acids (EFA). The data were compared to corresponding normal values. GSHPx was significantly decreased in the mitochondrial matrix from animals in all 3 deficiency states. In vitamin E deficiency, a nonsignificant decreased GSHPx activity was found in mitochondrial membranes. Opposite to these findings, GSHPx was significantly increased in mitochondrial membranes of EFA-deficient animals. In combined EFA and vitamin E deficiency, the mitochondrial membrane GSHPx activity was only insignificantly increased. The P-450 complex activity was not detectable in the mitochondrial matrix. In mitochondrial membranes and microsomes, the P-450 complex activity changed parallel to the GSHPx activity.