Abstract
The utilization of ubiquinone with 7 isoprenoide units (UQ_7) was investigated following administration into mice. When UQ_7-(methoxy)-^<14>C was given either intraperitoneally, intramusclarly, subcutaneously or directly into the portal vein, the radioactive material was retained and circulated in the blood for a prolonged period of time, and was gradually incorporated into various tissues and organs. A large portion of the radioactivity, however, was found to be excreted into the intestinal tract by way of bile duct. Practically no radioactive material was found in the urine. When UQ_7-^<14>C was given orally, more than 80% of the total radioactivity was excreted in the feces within 24 hours. Approximately 1% was absorbed and distributed in various tissues and organs. Subcellular fractionation analysis revealed that the intracellular radioactive UQ_7 was almost exclusively localized in mitochondria without elongation of the isoprenoid chain as judged by thin layer chromatography.
