coenzyme-q10 and Hemolysis

Plasma coenzyme Q10 (CoQ10) is currently assayed in our laboratory for its well-known diagnostic meaning; in fact plasma CoQ10 levels are inversely related to metabolic demand. Definite levels of CoQ10 are also found in white and red blood cell components, as well as in platelets. Plasma and erythrocyte CoQ10 has a well assessed antioxidant role, which was demonstrated through a series of experiments. Erythrocytes previously enriched with exogenous CoQ10 were found more resistant to a hemolysis induced by a free radical initiator. Several enzymatic activities of erythrocyte ghosts were also protected by different side chain CoQ homologues, both when reduced and, although at a lesser extent, in the oxidized state. CoQ was not effective in preventing metal-catalyzed oxidation of erythrocyte membrane enzymes, and this effect is likely to be due to lack of interaction of CoQ with the metal target. Moreover CoQ was able to protect isolated enzymes and erythrocyte membrane bound enzymes from the inactivating effect of free radicals generated by water sonolysis or radiolysis. As far as plasma lipoproteins are concerned it is well known that LDL isolated from healthy volunteers supplemented with CoQ10 are more resistant to peroxidation induced by an azoinitiator. We started to systematically investigate CoQ10 and vitamin E levels in isolated human LDL and HDL. Both CoQ10 and vitamin E concentrations, referred to protein, were found higher in LDL than in HDL. Susceptibility to exogenously applied peroxidation did not correlate with the endogeneous content of the two antioxidants, possibly on the basis of different lipid content of these lipoproteins.

Topics: Alkaline Phosphatase; Animals; Blood Cells; Coenzymes; Erythrocytes; Free Radicals; Hemolysis; Humans; Lipid Peroxidation; Lipoproteins; Oxidation-Reduction; Oxidative Stress; Plasma; Rats; Sodium-Potassium-Exchanging ATPase; Ubiquinone

Whole blood vitamin Q (ubiquinone), plasma vitamins Q and E (alpha-(alpha-)tocopherol) and free cholesterol (FC) were studied before (control or base-line value, sample I) and during open chest surgery and extracorporal circulation (samples II-IV) in 10 male IHD patients. Identity existed between control whole blood and plasma ubiquinone. During surgery an increased discrepancy with lower plasma vitamin Q levels were seen. Control plasma vitamins Q, E and FC averaged 0.88 +/- 0.16 (SE), 12.1 +/- 2.2 mg x l(-1) and 0.75 +/- 0.15 g x l(-1). Corresponding molar values were 1.02 +/- 0.17, 28.1 +/- 5.1 micromol x l(-1) and 1.94 +/- 0.74 mmol x l(-1). Vitamin Q and E decreased continuously and averaged 0.64 mg x l(-1) in sample IV (0.74 micromol x l(-1), p < 0.001) and 9.4 mg x l(-1) in sample III (21.8 micromol x l(-1), p < 0.001). Hemolysis in all sample IV vials, ruined all vitamin E determinations. When normalized for FC (NQ and NE), decreases were found to be 17 (IV) and 12% (III), respectively. Large interindividual variations existed. High control NQ and NE values allowed a larger antioxidant vitamin depletion. High NQ seemed also to be a prerequisite for NE depletion. In addition, signs indicated an active liver vitamin Q release for patients rich in control antioxidant values. It was suggested that the antioxidant vitamin depletion did not prevent from radical trauma to membrane structural lipids (especially omega-3 fatty acids or vitamin F1), less membrane fluidity, erythrocyte fragility and hemolysis.

Topics: Aged; Cholesterol; Extracorporeal Circulation; Hemodilution; Hemolysis; Humans; Male; Middle Aged; Myocardial Ischemia; Organic Chemicals; Reference Values; Ubiquinone; Vitamin E; Vitamins

Using dog erythrocytes, the effect of coenzyme Q10 (CoQ10) on the resistance of the erythrocyte membrane was investigated. Hemolysis was induced either by Octoxinol (Triton X-100) a well-known detergent, or by hypotonic salines. Although no detectable CoQ10 was observed in erythrocyte without CoQ10 addition, the increment in CoQ10 content in erythrocyte was found to be proportional to the doses of CoQ10 added to the erythrocyte samples. Administration of CoQ10 inhibited significantly the hemolysis induced either by octoxinol or hypotonic salines by a dose-dependent manner. These results suggest that CoQ10 incorporated into the erythrocyte increased the resistance of erythrocyte membrane by a direct structural effect on the membrane.

Topics: Animals; Coenzymes; Detergents; Dogs; Erythrocytes; Hemolysis; Hypotonic Solutions; In Vitro Techniques; Octoxynol; Polyethylene Glycols; Sodium Chloride; Ubiquinone