the fully reduced form of ubiquinone. CoQH2 reduces other
carriers of reducing equivalents, such as the cytochromes
in the mitochondria, thereby supporting ATP production.
CoQH2 also functions on the cell membrane to recharge
spent antioxidants with hydrogen atoms.
a benzoquinone naturally occuring in all living things;
the agent of transfer of reducing equivalents between the
flavins and the cytochromes in the mitochondria. The number
2,3,5 and 6 carbon positions are protected against
alkylation by bound radicals. Types of ubiquinone are
distinguished according to the number of isoprenoid groups
in the long lipophilic side chain. For example, if there
is a decaprenyl group at position 6, such a ubiquinone
is abbreviated CoQ10.
ultraviolet hemoirradiation therapy (UVHIT):
a medical procedure in which blood is drawn out of the body,
anticoagulated, exposed to ultraviolet light, and then
reinfused. The procedure is profoundly antiinfective. It is
thought to work by the production of singlet oxygen which
immediately reacts with blood components. The products go on
to induce certain antiinfective/immunostimulatory effects.
UVHIT may also function by photoreduction of the pi bonds
of numerous molecules in the treated blood. Such a process
would deplete hydrogen atoms from various hydorgen carriers
in the treated blood.
the wavelengths or frequencies of light absorbed by the
compound being examined; the distribution of colors absorbed
or transmitted upon exposure to ultraviolet and visual light.
Molecules with conjugated double bonds are most likely to
absorb light somewhere in the ultraviolet or visual bands.
The spectral analysis changes if there is any change in the
conjugated bond system of the molecule. Such occurs readily
upon reduction or oxidation of such molecules. This test is
useful in chemical analyses and in enzymology. The function
of oxidoreductases can be analyzed according to specific
color changes which occur as the enzyme shifts between reduced
and oxidized phases. FAD for example is bright yellow when
oxidized. Upon reduction to FADH2, it turns colorless.