Blood concentration of coenzyme Q(10) increases in rats when esterified forms are administered

Coenzyme Q levels decrease during aging in most tissues and in the target o rgans of a number of diseases. The uptake of this lipid into the blood and other tissues was investigated in 6-wk-old male Sprague-Dawley rats after 3 wk of dietary supplementation. In addition to the natural form of coenzyme Q(10), acetylated and succinylated forms were also administered. Coenzyme Q(10) was taken up into the blood, but uptake was significantly greater in rats given the succinylated (similar to 40%), and particularly! the acetyla ted forms (similar to 70%). All three forms increased significantly the tot al coenzyme Q concentration in both the liver (similar to 100%) and spleen (similar to 130%). Coenzyme Q(10) and its esterified forms were not taken u p into kidney, heart, muscle or brain. Intraportal and intraperitoneal admi nistration of succinylated coenzyme Q(10) gave results similar to those obt ained in the dietary experiments. Uptake of the dietary coenzyme Q(10) into the liver and spleen did not down-regulate the endogenous synthesis, i.e., the amounts of isolated coenzyme Q(9) did not change in these tissues. Thu s, esterification of coenzyme Q increases the uptake of dietary lipid into the blood; however, the derivatization does not contribute to the elevation of coenzyme Q levels in various organs.