Coenzyme Q
Cofactors

Author: Gianpiero Pescarmona
Date: 2008-07-29

Description

Coenzyme Q10 (also known as ubiquinone, coenzyme Q, CoQ10) is a 1,4-benzoquinone, where Q refers to the quinone chemical group, and 10 refers to the number of isoprenyl subunits.

DatabaseLink
Human Metabolome DatabaseCoQ
Linus PaulingCoQ

It is present in most eukaryotic cells, primarily in the mitochondria as a component of the electron transport chain. As ninety-five percent of the human body’s energy is generated this way, the cellular level of CoQ plays a critical role in cell function. Therefore, those organs with the highest energy requirements—such as the heart and the liver—have the highest CoQ10 concentrations
Coenzyme Q10 is also a powerful endogenous antioxidant.

Coenzyme Q10: A Review of Essential Functions

CoEnzyme Q10 (Ubiquinone, Ubiquinol and Semiquinone) by Ben Best

Coenzyme Q (Q) functions in the mitochondrial respiratory chain and serves as a lipophilic antioxidant. There is increasing interest in the use of Q as a nutritional supplement. Although the physiological significance of Q is extensively investigated in eukaryotes, ranging from yeast to human, the eukaryotic Q biosynthesis pathway is best characterized in the budding yeast Saccharomyces cerevisiae. At least ten genes (COQ1-COQ10) have been shown to be required for Q biosynthesis and function in respiration. Recent knowledge about the endogenous synthesis of Q in eukaryotes, with emphasis on S. cerevisiae as a model system

Clinical role CoQ level

  • a low level of ubiquinone in the plasma of patients with a chronic heart failure has been considered a predictor factor of increased mortality [Molyneux et al, 2008].
Comments
2008-07-29 16:53:21.165515 - Gianpiero Pescarmona

Chin J Physiol. 2007 Oct 31;50(5):217-24.Links
Click here to read

Erratum in:
Chin J Physiol. 2007 Dec 31;50(6):330.

Effects of coenzyme Q10 on the heart ultrastructure and nitric oxide synthase during hyperthyroidism.
Oztay F, Ergin B, Ustunova S, Balci H, Kapucu A, Caner M, Demirci C.

Department of Biology, Faculty of Science, Istanbul University, Vezneciler. fusunoztay@yahoo.com

Coenzyme Q10 is an important component of mitochondrial electron transport chain and antioxidant. Hyperthyroidism manifests hyperdynamic circulation with increased cardiac output, increased heart rate and decreased peripheral resistance. The heart is also under the oxidative stress in the hyperthyroidism. The aim of this study was to examine both how the coenzyme Q10 can affect heart ultrastructure in the hyperthyroidism and how the relationship between nitric oxide synthase (NOS) and heart damage and coenzyme Q10. Swiss Black C57 mice received 5 mg/kg L-thyroxine. Coenzyme Q10 (1.5 mg/kg) and L-thyroxine together was given to second group mice. Coenzyme Q10 and serum physiologic were applied to another two groups, respectively. All treatments were performed daily for 15 days by gavage. Free triiodothyronine and thyroxine were increased in two groups given L-thyroxine; thyroid-stimulating hormone level did not change. Hyperthyroid heart showed an increased endothelial NOS (eNOS) and inducible NOS (iNOS) immunoreactivity in the tissue. Coenzyme Q10 administration decreased these NOS immunoreactivities in the hyperthyroid animals. Cardiomyocytes of the hyperthyroid animals was characterized by abnormal shape and invaginated nuclei, and degenerative giant mitochondria. Desmosome plaques reduced in density. In hyperthyroid mice given coenzyme Q10, the structural disorganization and mitochondrial damage regressed. However, hearts of healthy mice given coenzyme Q10 displayed normal ultrastructure, except for increased mitochondria and some of them were partially damaged. Coenzyme Q10 increased the glycogen in the cardiomyocytes. In conclusion, coenzyme Q10 administration can prevent the ultrastructural disorganization and decrease the iNOS and eNOS increment in the hyperthyroid heart.