Distribution of ubiquinone and ubiquinol homologues in rat tissues and subcellular fractions

Abstract

The oxidized (UQox) and reduced (UQred) forms of ubiquinone (UQ) homologues in rat tissues and subcellular fractions were analyzed to elucidate their distribution and physiological role. UQ-9 and UQ-10 were detected in all tissues studied, and UQ-9 was the predominant homologue. The total amount of UQox-10 and UQred-10 was 20-50% that of UQox-9 and UQred-9. The levels of these homologues were highest in heart with lesser amounts occurring in kidney, liver and other organs. In liver and blood plasma, the UQred homologue amounted to 70-80% of the total UQ (UQox + UQred = t-UQ). UQred was less than 30% of t-UQ in other tissues and blood cells. t-UQ was much higher in leukocytes and platelets in blood than in erythrocytes. In erythrocytes, t-UQ was exclusively located in the cell membranes. UQox and UQred were also found in all subcellular fractions isolated from liver and kidney in about the same ratio as UQred/t-UQ was present in the whole organ. The levels of UQox and UQred per mg protein in subcellular fractions from liver were highest in mitochondria, with lesser amounts present in plasma membranes, lysosomes, Golgi complex, nuclei, microsomes and cytosol. In the mitochondria, the outer membranes were richer in t-UQ than the inner membranes. In the Golgi complex, the light and intermediate fractions were rich in t-UQ when compared to the heavy fraction. The possible physiological role of UQox and UQred in tissues and subcellular fractions is discussed.

Comparison of Uptake between PureSorb-Q40 and Regular Hydrophobic Coenzyme Q10 in Rats and Humans after Single Oral Intake

“…CoQ9 and CoQ10 are widely distributed in the spleen, kidney, heart, liver and plasma. In the liver and plasma, the ratio of reduced CoQ to total CoQ (reduced and oxidized CoQ) is 70-80%, compared to 30% in other tissues (16). The present results did not show any marked differences in serum CoQ9 levels following oral intake of P40 or Q10 oil, and the ratio of reduced CoQ for CoQ9 and CoQ10 was 70-80%.…”

Evaluation of the Protective Effects of CoQ₁₀ on Ovarian I/R Injury: An Experimental Study

“…Because the majority of CoQ 10 is in the quinol form in the cell membranes [10], it can be an effective antioxidant [11]. Many studies on the inhibitory effects of CoQ 10 on lipid peroxidation exist in the literature [12,13,14].…”

Effects of Exercise and Food Consumption on the Plasma Oxidative Stress

“…It has been reported that the physiological effects of CoQ10 include the energy through the production of produces ATP with mitochondria activator and the anti-oxidant activity 18,19) . Recently, QH, which is a major CoQ10 in the body, has been put to commercial use and is reported to have such actions as antisenescence activity, which is different from that of oxidized CoQ10 6,11) . This study demonstrated that consumption of QH results in a significant increase in running time.…”

“…Oxidized CoQ10 is transformed by reduction enzymes into QH (H 2 CoQ10) in the body (especially in the blood plasma and the liver) of animals such as humans and rats, which means that QH is a major metabolic form of CoQ10 11) . As the percentage of QH in the body and the ability to transform oxidized CoQ10 into QH decrease with aging 12) , it has been reported that the action on the body by the consumption of QH has widely different physical effects from that by the consumption of oxidized CoQ10 6) .…”