Decreased ubiquinone levels in tissues of rats deficient in selenium.

The effect of selenium deficiency (-Se) on the levels of ubiquinones in liver, heart, kidney, and leg muscle was studied in the rat. Levels of ubiquinone 9 and ubiquinone 10 in the liver of -Se rats were about 50% of the levels in selenium adequate animals. Both ubiquinones in the heart were about 15% lower in -Se rats. Only ubiquinone 9 was significantly lower in the kidney of -Se rats. There was no difference in ubiquinone levels in leg muscle. Glutathione peroxidase activity in the tissues of -Se rats was > 95% lower. It is concluded that Se, as an integral part of the enzyme glutathione peroxidase, may protect tissues from oxidative damage, thereby preserving the ability of the cells to synthesize ubiquinone and preventing ubiquinone from oxidative degradation.