Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The juvenile type of neuronal ceroid lipofuscinosis (JNCL) is a recessively inherited, progressive neurodegenerative disease. In this study the levels of the antioxidant factors coenzyme Q10 (CoQ10) and vitamin E (alpha-tocopherol) were measured in plasma samples of 29 JNCL patients and compared to 48 healthy controls. A significant reduction of the coenzyme Q10 level (0.59 +/- 0.25 microgram/ml) was observed in JNCL patients when compared to control subjects (0.80 +/- 0.26 microgram/ml). The level of vitamin E was also reduced markedly in JNCL patients when compared to controls (10.4 +/- 4.1 and 12.1 +/- 4.5 micrograms/ml, respectively). The low levels of CoQ10 and vitamin E in JNCL patients may indicate an impaired antioxidant protection in this disease.
Mol Aspects Med 1997
PMID:Evaluation of the possible role of coenzyme Q10 and vitamin E in juvenile neuronal ceroid-lipofuscinosis (JNCL). 926 33

In beef heart mitochondria it has been found that the Km for coenzyme Q10 of the NADH oxidation system is in the range of the membrane concentration of the quinone; this is contrary to succinate oxidation which is in Vmax with respect to quinone content. The same proportional difference between the two systems is maintained in their affinities for the exogenous acceptor CoQ1 in non-extracted mitochondria. The Km of succinate- coenzyme Q reductase for CoQ1 is reversibly lowered in CoQ-depleted mitochondria; while in contrast the Km for NADH-coenzyme Q reductase is reversibly increased by CoQ extraction. Incorporation of exogenous quinones by co-sonication with submitochondrial particles, as evidenced by fluorescence quenching of pyrene, enhances NADH-cytochrome c reductase activity in accordance with the lack of saturation of the former system.
Mol Aspects Med 1997
PMID:Saturation kinetics of coenzyme Q in NADH oxidation: rate enhancement by incorporation of excess quinone. 926 35

The coenzyme Q8 (CoQ8) and alpha-tocopherol contents of different mitochondrial fractions were investigated from occipital cerebral cortices of different ages. The highest CoQ8 and vitamin E concentrations were found in non-synaptic free mitochondria (FM) fractions. In several cases heavy mitochondria (HM) fractions displayed the lowest values. Occipital cerebral cortex mitochondria contained higher CoQ9 and lower CoQ10 amounts than those typical for other brain regions.
Mol Aspects Med 1997
PMID:Coenzyme Q homologs and vitamin E in synaptic and non-synaptic occipital cerebral cortex mitochondria in the ageing rat. 926 37

Coenzyme Q10 supplementation (Bio-Qinon Pharma Nord, 90 mg/day) was studied in a double-blind cross-over study of 25 Finnish top-level cross-country skiers. With CoQ10 supplementation, all measured indexes of physical performance (AET, ANT and VO2Max) improved significantly. During verum supplementation, 94% of the athletes felt that the preparation had been beneficial in improving their performance and recovery time vs. only 33% in the placebo periods.
Mol Aspects Med 1997
PMID:The effect of coenzyme Q10 on the exercise performance of cross-country skiers. 926 38

The effects of oral supplementation of 100 mg coenzyme Q10 (CoQ10) for 6 months on muscle energy metabolism during exercise and recovery were evaluated in middle-aged post-polio (n = 3) and healthy subjects (n = 4) by the use of phosphorus-31 nuclear magnetic resonance spectroscopy. The metabolic response to isometric plantar flexion at 60% of maximal voluntary contraction force (MVC) for 1.5 min was determined in gastrocnemius muscles before, after 3- (3MO) and 6-month (6MO) of CoQ10 supplementation. The MVC of plantar flexion was unchanged following CoQ10 supplementation. The resting Pi/PCr ratio in gastrocnemius muscles of all subjects decreased after 3MO- and 6MO-CoQ10 (P < 0.05). The post-polio individuals showed a progressive decrease in this ratio, while less pronounced changes were observed in the control subjects. Similarly, the post-polio individuals showed a lower Pi/PCr ratio at the end of 60% MVC in both 3MO- and 6MO-CoQ10, whereas no change in the ratio was observed in the control subjects. A less pronounced decrease in muscle pH was observed at the end of 60% MVC in both 3MO- and 6MO-CoQ10 in the post-polio individuals, but not in the control subjects. No systematic difference in end-exercise ATP was observed between the three phases in both groups. The half-time of recovery for PCr decreased in all subjects after 6MO-CoQ10 supplementation (P < 0.05). The results suggest that CoQ10 supplementation affects muscle energy metabolism in post-polio individuals to a greater extent than in control subjects. The mechanism for this effect is not clear, but may involve an effect of CoQ10 on peripheral circulation in the calf muscles, its action in mitochondrial oxidative phosphorylation and/or its antioxidant potential.
Mol Aspects Med 1997
PMID:Effects of oral supplementation of coenzyme Q10 on 31P-NMR detected skeletal muscle energy metabolism in middle-aged post-polio subjects and normal volunteers. 926 39

Coenzyme Q10 (CoQ10) is a critical adjuvant therapy for patients with congestive heart failure (CHF), even when traditional medical therapy is successful. Adjunctive therapy with Q10 may allow for a reduction of other pharmacological therapies, improvement in quality of life, and a decrease in the incidence of cardiac complications in congestive heart failure. However, dosing, clinical application, bioavailability and dissolution of CoQ10 deserve careful scrutiny whenever employing the nutrient. The assessment of blood levels in 'therapeutic failures' appears warranted.
Mol Aspects Med 1997
PMID:Refractory congestive heart failure successfully managed with high dose coenzyme Q10 administration. 926 40

alpha-Tocopherolquinone (TQ), a product of alpha-tocopherol oxidation, can function as an antioxidant after reduction to alpha-tocopherolhydroquinone (TQH2). We examined the ability of human NAD(P)H:quinone oxidoreductase (NQO1) to catalyze the reduction of TQ to TQH2 in cell-free and cellular systems. In reactions with purified human NQO1, TQ was reduced to TQH2. Kinetic parameters for the reduction of TQ by NQO1 (Km = 370 microM; k(cat) = 5.6 x 10(3) min(-1); k(cat)/Km = 15 min(-1) x microM(-1)) indicate that NQO1 can efficiently reduce TQ to TQH2. A comparison of the rate of reduction of TQ and coenzyme Q10 by NQO1 showed that TQ is reduced more efficiently than coenzyme Q10. Experiments with either Chinese hamster ovary (CHO) cells stably transfected with human NQO1 or CHO cell sonicates demonstrated a correlation between NQO1 activity and TQ reduction to TQH2. CHO cells with elevated NQO1 generated and maintained higher levels of TQH2 after treatment with TQ relative to NQO1-deficient CHO cells. TQH2 generated from NQO1-mediated reduction of TQ prevented cumene hydroperoxide-induced lipid peroxidation in rat liver microsomes. In addition, cumene hydroperoxide-induced lipid peroxidation was inhibited more efficiently by TQ in CHO cell lines with elevated NQO1 activity. These data demonstrate that NQO1 can reduce TQ to TQH2 and that TQH2 can function as an efficient antioxidant. This work suggests that one of the physiological functions of NQO1 may be to regenerate antioxidant forms of alpha-tocopherol.
Mol Pharmacol 1997 Aug
PMID:The reduction of alpha-tocopherolquinone by human NAD(P)H: quinone oxidoreductase: the role of alpha-tocopherolhydroquinone as a cellular antioxidant. 927 53

With phosphorus magnetic resonance spectroscopy (31P-MRS) we studied in vivo the effect of six-month coenzyme Q10 treatment on the efficiency of brain and skeletal muscle mitochondrial respiration in six patients with different mitochondrial cytopathies. Before CoQ we found a low phosphocreatine content (average of 25% decrease from controls) in the occipital lobes of all patients. Calculated [ADP] and the relative rate of ATP synthesis were high (as an average, 57% and 16% above control group respectively), whereas the cytosolic phosphorylation potential was low (as an average, 60% of control value). 31P-MRS also revealed an average of 29% reduction of the mitochondrial function in the skeletal muscle of patients compared with controls. After a six-month treatment with 150 mg CoQ10/day all brain variables were remarkably improved in all patients, returning within the control range in all cases. Treatment with CoQ also improved the muscle mitochondrial functionality enough to reduce the average deficit to 56% of the control group. These in vivo findings show the beneficial effect of CoQ in patients with mitochondrial cytopathies, and are consistent with the view that increased CoQ concentration in the mitochondrial membrane increases the efficiency of oxidative phosphorylation independently of enzyme deficit.
Cell Mol Biol (Noisy-le-grand) 1997 Jul
PMID:Coenzyme Q10 improves mitochondrial respiration in patients with mitochondrial cytopathies. An in vivo study on brain and skeletal muscle by phosphorous magnetic resonance spectroscopy. 929 96

Coenzyme Q10 is an endogenous lipid soluble antioxidant. Because oxidant stress may exacerbate some complications of diabetes mellitus, this study investigated the effects of subacute treatment with exogenous coenzyme Q10 (10 mg/kg/day, i.p. for 14 days) on tissue antioxidant defenses in 30-day streptozotocin-induced diabetic Sprague-Dawley rats. Liver, kidney, brain, and heart were assayed for degree of lipid peroxidation, reduced and oxidized glutathione contents, and activities of catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase. All tissues from diabetic animals exhibited increased oxidative stress and disturbances in antioxidant defense when compared with normal controls. Treatment with the lipophilic compound coenzyme Q10 reversed diabetic effects on hepatic glutathione peroxidase activity, on renal superoxide dismutase activity, on cardiac lipid peroxidation, and on oxidized glutathione concentration in brain. However, treatment with coenzyme Q10 also exacerbated the increase in cardiac catalase activity, which was already elevated by diabetes, further decreased hepatic glutathione reductase activity, augmented the increase in hepatic lipid peroxidation, and further increased glutathione peroxidase activity in the heart and brain of diabetic animals. Subacute dosing with coenzyme Q10 ameliorated some of the diabetes-induced changes in oxidative stress. However, exacerbation of several diabetes-related effects was also observed.
J Biochem Mol Toxicol 2001
PMID:Effects of coenzyme Q10 treatment on antioxidant pathways in normal and streptozotocin-induced diabetic rats. 1117 Mar 14

In a randomized, double-blind, controlled trial, the effects of oral treatment with coenzyme Q10 (CoQ10, 120 mg/day), a bioenergetic and antioxidant cytoprotective agent, were compared for 1 year, on the risk factors of atherosclerosis, in 73 (CoQ, group A) and 71 (B vitamin group B) patients after acute myocardial infarction (AMI). After 1 year, total cardiac events (24.6 vs. 45.0%, p < 0.02) including non-fatal infarction (13.7 vs. 25.3%, p < 0.05) and cardiac deaths were significantly lower in the intervention group compared to control group. The extent of cardiac disease, elevation in cardiac enzymes, left ventricular enlargement, previous coronary artery disease and elapsed time from symptom onset to infarction at entry to study showed no significant differences between the two groups. Plasma level of vitamin E (32.4 +/- 4.3 vs. 22.1 +/- 3.6 umol/L) and high density lipoprotein cholesterol (1.26 +/- 0.43 vs. 1.12 +/- 0.32 mmol/L) showed significant (p < 0.05) increase whereas thiobarbituric acid reactive substances, malondialdehyde (1.9 + 0.31 vs. 3.1 + 0.32 pmol/L) and diene conjugates showed significant reduction respectively in the CoQ group compared to control group. Approximately half of the patients in each group (n = 36 vs. 31) were receiving lovastatin (10 mg/day) and both groups had a significant reduction in total and low density lipoprotein cholesterol compared to baseline levels. It is possible that treatment with CoQ10 in patients with recent MI may be beneficial in patients with high risk of atherothrombosis, despite optimal lipid lowering therapy during a follow-up of 1 year. Adverse effect of treatments showed that fatigue (40.8 vs. 6.8%, p < 0.01) was more common in the control group than CoQ group.
Mol Cell Biochem 2003 Apr
PMID:Effect of coenzyme Q10 on risk of atherosclerosis in patients with recent myocardial infarction. 1284 46


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>