QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zhang, Y. Articles by Ernster, L. Search for Related Content PubMed PubMed Citation Articles by Zhang, Y. Articles by Ernster, L.

Uptake of Dietary Coenzyme Q Supplement is Limited in Rats^1,2,

Yiyi Zhang^*, Fredrik Åberg, Eeva-Liisa Appelkvist^*,3, Gustav Dallner^*,, and Lars Ernster

^* Division of Medical Cell Biology, Clinical Research Center, Karolinska Institutet, Novum, S-141 86 Huddinge Department of Biochemistry, University of Stockholm, S-106 91 Stockholm, Sweden

Coenzyme Q is an important mitochondrial redox component and the only endogenously produced lipid-soluble antioxidant. Its tissue concentration decreases with aging and in a number of diseases; dietary supplementation of this lipid would fulfill important functions by counteracting coenzyme Q depletion. To investigate possible uptake, rats were administered 12 µmol coenzyme Q₁₀/100 g body wt once daily by gastric intubation. The appearance of coenzyme Q₁₀ in various tissues and blood after 6 h, 4 d or 8 d was studied. The control group of rats received rapeseed-soybean oil (the vehicle in the experimental group). Lipids were extracted with petroleum ethermethanol, and the reduced and oxidized forms of coenzyme Q₉ and Q₁₀ were separated and quantified by reversed-phase HPLC. In the plasma, the total coenzyme Q concentration was doubled after 4 d of treatment. Coenzyme Q₁₀ was also recovered in liver homogenates, where, as in the plasma, it was largely in the reduced form. Uptake into the spleen could be to a large extent accounted for by the blood content of this organ. No dietary coenzyme Q₁₀ was recovered in the heart or kidney. The uptake in the whole body was 2–3% of the total dose. Coenzyme Q₁₀ found in the liver was located mainly in the lysosomes. Dietary coenzyme Q₁₀ did not influence the endogenous biosynthesis of coenzyme Q₉. This is in contrast to dietary cholesterol, which down-regulates cholesterol biosynthesis. The dietary coenzyme Q₁₀ level in the plasma decreased to -50% after 4 d. These results suggest that dietary coenzyme Q₁₀ may play a role primarily in the blood and that no appreciable uptake occurs into tissues.

KEY WORDS: • coenzyme Q • liver • plasma • heart • rats

¹ Supported by the Swedish Cancer Society and the Swedish Medical Research Council.

² The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 USC section 1734 solely to indicate this fact.

³ To whom correspondence should be addressed.

Manuscript received 17 May 1994. Revision accepted 24 August 1994.