Effects of coenzyme Q₁₀ and α-tocopherol administration on their tissue levels in the mouse: Elevation of mitochondrial α-tocopherol by coenzyme Q₁₀

Coenzyme Q (CoQ) was previously demonstrated in vitro to indirectly act as an antioxidant in respiring mitochondria by regenerating α-tocopherol from its phenoxyl radical. The objective of this study was to determine whether CoQ has a similar sparing effect on α-tocopherol in vivo. Mice were administered CoQ₁₀ (123 mg/kg/day) alone, or α-tocopherol (200 mg/kg/day) alone, or both, for 13 weeks, after which the amounts of CoQ₁₀, CoQ₉ and α-tocopherol were determined by HPLC in the serum as well as homogenates and mitochondria of liver, kidney, heart, upper hindlimb skeletal muscle and brain. Administration of CoQ₁₀ and α-tocopherol, alone or together, increased the corresponding levels of CoQ₁₀ and α-tocopherol in the serum. Supplementation with CoQ₁₀ also elevated the amounts of the predominant homologue CoQ₉ in the serum and the mitochondria. A notable effect of CoQ₁₀ intake was the enhancement of α-tocopherol in mitochondria. α- Tocopherol administration resulted in an elevation of α-tocopherol content in the homogenates of nearly all tissues and their mitochondria. Results of this study thus indicate that relatively long-term administration of CoQ₁₀ or α-tocopherol can result in an elevation of their concentrations in the tissues Of the mouse. More importantly, CoQ₁₀ intake has a sparing effect on α-tocopherol in mitochondria in vivo.