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Current Neurobiology

Preventive and Therapeutic Coenzyme Q10 Supplementation In Rat Subjected to Cerebrovascular Ischemia-Reperfusion Injury

Author(s): Horecký J, Aliev G, Gvozdjáková A, Kucharská J, Vančová O

Vol. 1, No. 1 (2010-01 - 2010-06)

Current Neurobiology 2010 1 (1): 30-36

Horecký J1, Aliev G2, Gvozdjáková A3, Kucharská J3, Vančová O3

(1) Surgical Pathophysiology and Tissue Engineering Center, Slovak Medical University,Bratislava, Slovak Republic
(2) Department of Biology, College of Sciences, University of Texas at San Antonio, SanAntonio, Texas 78249, USA
(3) Pharmacobiochemical Laboratory of the 3rd Internal Medicine Department, Comenius University School of Medicine, Bratislava, Slovak Republic

Key Words: Rat; three-vessel occlusion; coenzyme Q10; endogenous antioxidants; TBARS
Accepted November 14 2009

Abstract

It is known that oxidative stress and mitochondrial dysfunction plays an important role in animal models of brain ischemia. The present study was undertaken to test whether oral supplementation of coenzyme Q (CoQ) could protect against transient cerebral ischemia-induced mitochondrial damage in the rat brain. Rats were divided into four groups: 1- control; 2- ischemia-reperfusion; 3- CoQ before ischemia; 4- CoQ after ischemia. Transient cerebral ischemia was induced with three vessel occlusion (3-VO) for 50 min. CoQ (200 mg/kg/day, p.o.) was administered for 30 days before ischemia and/or for 30 days after ischemia. Brain mitochondria were used for the determination of oxidative phosphorylation (OXPHOS). Moreover, the concentrations of CoQ and tocopherols, and formation of TBARS were measured in brain mitochondria and in plasma. Ischemia-reperfusion injury revealed significant impairment of OXPHOS, decreased concentrations of brain and plasma endogenous antioxidants and increased formation of TBARS in plasma. When compared with ischemia-reperfusion group, preventive supplementation of CoQ was ineffective. However, positive effect of therapeutic CoQ supplementation was detected in RCI (P<0.001), S3 (P<0.05) and in OPR (P<0.05), as well as in the concentration of coenzyme Q9 in brain mitochondria (P<0.05) and of α-tocopherol (P<0.01) in plasma. This suggests that the protection of CoQ10 involve increased resistance to oxidative stress, when supplemented during reperfusion.

Introduction

Normal brain function is highly dependent on adequate blood flow and substrate delivery for production of ATP in mitochondria. Impaired cerebral perfusion originating in the microvasculature affects the optimal delivery of glucose and oxygen resulting in a breakdown of metabolic energy pathways in brain cells [1,2] Free radical formation has been demonstrated not only during cerebral ischemia [3,4], but much more at the onset of reperfusion after cerebral ischemia [5,6].

Many antioxidants are reported to reduce ROS-mediated reactions in animal models of cerebral ischemia, however, the preventive and therapeutic effect of CoQ10 supplementation on cerebral ischemia and reperfusion has not been evaluated. Therefore, the present study was designed to investigate the effect of CoQ10 supplementation on ischemia and reperfusion-induced mitochondrial injury in rats subjected to transient three-vessel occlusion (3-VO).

Materials and Methods

Animals

Adult (18 month old) male Wistar rats, weighing 460-550 g , obtained from VELAZ (Prag, Czech Republic), were maintained at 22 ± 2 0C, 45 relative humidity, 12 hour light/dark cycle in air conditioned room with free access to standard commercial rodent pellet diet ST 1 (TOP DOVO, Slovak Republic) and tap water ad libitum. The protocol of this study has been approved by Slovak Medical University Ethics Committee in compliance with the Guidelines of European Convention for the Protection of Vertebrate Animals Used for Experimental Purposes.

Experimental design

Rats were divided into four experimental groups

1. C- control group without treatment (n=6)
2. IR- 50-min 3-VO + 30-day reperfusion (n=6)
3. Q10+ IR- preventive treatment with liposoluble CoQ10 (Li-Q-SorbTM, Tishcon corp.,USA) in daily dose 200 mg/kg bw for 30 days before IR injury (n=6)
4. IR + Q10- therapeutic treatment with CoQ10 by gavage in daily dose 200 mg/kg bw for 30 days after 50-min ischemia (n=6)

Transient brain ischemia was induced with occlusion of both, truncus brachiocephalicus and left common carotid artery (three vessel occlusion, 3-VO) for 50 minutes. At the end of 30-day reperfusion, animals were euthanized (Thiopental 160 mg/kg i.p.) and the brain was removed for biochemical studies.

Three cerebral vessel occlusion (3-VO)

Experiments were done in aged male Wistar rats under general anesthesia (ketamine 50 mg/kg b.w. and xylazine 4 mg/kg b.w.) placed in a supine position on the operating table, and left to respire spontaneously. Transient ischemia-reperfusion injury was accomplished by our original surgical procedure for three-vessel occlusion (3-VO) [7,8]. Briefly, minimally invasive transmanubrial approach was used for occlusion of both, the left common carotid and brachiocephalic trunk (including right common carotid and right vertebral artery) to eliminate cerebral blood flow through both common carotid and right vertebral arteries. At the end of the 50-min period, the microaneurysmal clips were released to restore cerebral blood flow. After completion of surgical procedure and recovery, the animals were shifted to their home cage.

In vitro mitochondrial respiration

After euthanasia (Thiopental, Spofa, Czech Republic, 150 mg/kg.b.w.), brain was removed and placed on ice-cold isolation solution containing (in mmol.l-1) 225 manitol, 75 sucrose, 0.2 EDTA; pH 7.4. Tissue sample was minced and homogenized in the solution using a glass-teflon homogenizer. Brain mitochondria were isolated at 4oC by differential centrifugation [9]. Mitochondrial protein concentration was estimated by the method of Lowry et al [10] using bovine serum albumin as a standard. Respiratory chain function was measured in a respiratory buffer containing (in mmol.l-1) 12.5 HEPES, 3 KH2PO4, 122 KCl, 0.5 EDTA and 2% dextran; pH 7.2 at 30oC, by means of Oxygraph Gilson 5/6H (USA) using Clark-type polarographic oxygen electrode. Sodium glutamate/malic acid (2.5 mmol/2.5 mmol) were used as a NAD substrate for complex I. To initiate state 3 respiratory activity, 500 nmol of ADP were added to the cuvette.When all the ADP was converted to ATP, state 4 respiration was measured. Parameters of oxidative phosphorylation, such as QO2 [nAtO.mg prot-1.min-1], i.e., oxygen consumption rate in presence of ADP (state S3), oxygen consumption rate without ADP (state4); RCR [S3.S4], respiratory control ratio; ADP:O [nmol ADP . nAtO-1], coefficient of oxidative phosphotylation; and OPR [nmol ATP.mg prot.min-1], oxidative phosphorylation rate, were determined, respectively.

Determination of antioxidants

Concentrations of oxidized forms of CoQ9, CoQ10, α- and γ- tocopherols were determined by isocratic high-performance liquid chromatography (HPLC, LKB, Sweden) according to Lang et al. [11] with some modifications [12]. Plasma samples and isolated brain mitochondria were vortexed twice for 5 minutes with the mixture of hexane/ethanol (5/2, v/v, Merck, Germany). Collected organic layers were evaporated under nitrogen, the residues were taken up in ethanol and injected into Separon SGX C18 7 μm 3×150 mm column (Tessek, Czech Republic). Elution was performed with methanol/ acetonitril/ethanol (6/2/2, v/v, Merck, Germany). The concentration of tocopherols were detected spectrophotometrically at 295 nm, concentration of coenzyme Q homologues at 275 nm using external standards (Sigma, Germany). Data were collected and processed using CSW 32 chromatographic station (Data Apex Ltd, Czech Republic). Concentration of compounds in plasma were calculated in μmol.l-1, in mitochondria in nmol.mg prot-1.

Measurement of lipid peroxidation

Lipid peroxidation in plasma and brain homogenates was determined spectrophotometrically by measuring the formation of thiobarbituric acid reactive substances (TBARS) according to methods of Ohkawa et al. (13) and Janero and Burghardt (14). Plasma samples or brain homogenate were mixed with ice-cold 76% trichloacetic acid (TCA, Merck, Germany) and 1.07% thiobarbituric acid (TBA, Merck, Germany). Samples were incubated at 100oC and after cooling 90% TCA was added. After vortexing and centrifugation the absorbance of supernatant was measured at 532 nm using spectrophotometer Novaspec II Rapid (Pharmacia, LKB, Sweden). Concentration of lipid peroxides was expressed in plasma in μmol.l-1, in the brain tissue in nmol.g-1.

Statistical analysis

The results were evaluated using Student’s t-test for unpaired data, P<0.05 was considered statistically significant. Data are expressed as means ± standard deviation (S.D.). Statistical analysis was performed with one-way ANOVA followed by a Student’ t-test. The value of P less than 0.05 was considered to be statistically significant.

Results

Effect of coenzyme Q on ischemia and reperfusion-induced mitochondrial dysfunction The effects of-50 min cerebrovascular ischemia on rat brain mitochondria are shown in Tab. 1 and Fig. 1. Examination of oxidative phosphorylation revealed significant dysfunction of mitochondria from ischemia- reperfusion-treated group as demonstrated by the 21% decrease in oxygen consumption (QO2S3) and 24% decrease in the rate of ATP production (OPR), when compared with control group.

Preventive CoQ10 supplementation for 30 days before 50-min cerebrovascular occlusion was ineffective as documented by 26% decrease in oxygen consumption and 26% decrease of ATP production when compared to control and to ischemia-reperfusion groups. Therapeutic supplementation of CoQ10 for 30 days after 50-min ischemia demonstrated normal values of oxygen consumption and ATP production as in control group.

Table 1. Mitochondria respiration. Effect of coenzyme Q10 supplementation on oxidative phosphorylation in brain mitochondria of rats subjected to ischemia-reperfusion injury. RCI [S3.S4], respiratory control index; QO2S3, oxygen consumption rate in presence of ADP; OPR, oxidative phosphorylation rate. C, control group; IR, ischemia-reperfusion group; QIR, preventive supplementation of coenzyme Q10 for 30 days before cerebrovascular occlusion (3-VO); IRQ, therapeutic supplementation of coenzyme Q10 for 30 days of reperfusion. Values are expressed as mean ± S.E.M. ٭ = P<0.05 versus control group; + = P<0.05 versus ischemia-reperfusion group; x = P<0.05 versus preventive supplementation of CoQ10.

Parameters of oxidative phosphorylation Complex I

  RCI QO2S3 OPR
(S3.S4-1) (nAtO.mg prot-1.min-1) (nmol ATP.mg prot-1.min-1) Brain mitochondria
C 3.38 ± 0.26 62.80 ± 2.53 201.47 ± 8.42
IR 4.93 ± 0.31٭٭ 49.93 ± 5.76 153.55 ± 17.58٭
QIR 2.91 ± 0.17+++ 46.76 ± 1.16٭٭٭ 149.90 ± 8.22٭٭
IRQ 3.34 ± 1.13+++ 67.21 ± 5.37+ x 214.27 ± 20.66+ x
٭٭٭p<0.001, ٭٭ p<0.002, ٭p<0.05 vs C, +++p<0.001, +p<0.05 vs IR, xp<0.05 vs QIR

Effect of CoQ10 supplementation

Figure 1. Effect of CoQ10 supplementation on parameters of brain mitochondria respiration in rats subjected to ischemia-reperfusion injury. RCI, respiratory control index (S3.S4); QO2S3, oxygen consumption rate in presence of ADP (state 3); OPR, oxidative phosphorylation rate. C, control group; IR, ischemia (50 min 3-VO) – reperfusion(30 days) group; QIR, preventive supplementation of CoQ10 for 30 days before cerebral ischemia; IRQ, therapeutic supplementation of CoQ10 for 30 days after cerebral ischemia . Values are expressed as percentage of control group. ٭ = P < 0.05 versus control group;+=P < 0.05 versus ischemia –repefusion group; x = P < 0.05 versus preventive supplementation of CoQ10.

Table 2. Antioxidants. Effect of Coenzyme Q10 supplementation on the concentration of CoQ9, CoQ10, alpha and gamma tocopherol in brain mitochondria and in plasma of rats subjected to ischemia-reperfusion injury. C, control group; IR, ischemia-reperfusion group; QIR, preventive supplementation of CoQ10 for 30 days before cerebrovascular occlusion (3-VO); IRQ, therapeutic supplementation of Coenzyme Q10 for 30 days of reperfusion. Values are expressed as mean ± S.E.M. ٭ = P < 0.05 versus control group; + = P < 0.05 versus ischemia- reperfusion group; x = P < 0.05 versus preventive supplementation of CoQ10.

  CoQ9ox CoQ10ox α-tocopherol γ-tocopherol
Brain mitochondria (nmol.mg prot-1)
C 0.70 ± 0.03 0.34 ± 0.03 0.34 ± 0.06 0.05 ± 0.01
IR 0.71 ± 0.06 0.31 ± 0.04 0.23 ± 0.02 0.04 ± 0.01
QIR 0.62 ± 0.05 0.31 ± 0.01 0.22 ± 0.04 0.03 ± 0.01
IRQ 0.95 ± 0.07٭ + xx 0.34 ± 0.02 0.32 ± 0.02 +  
Plasma (μmol.l-1)
C 0.98 ± 0.19 n.d. 13.49 ± 1.90 0.08 ± 0.01
IR 0.40 ± 0.05٭ n.d. 10.46 ± 0.90 0.12 ± 0.02
QIR 0.59 ± 0.28 1.63 ± 0.29 14.52 ± 1.15+ 0.06 ± 0.01+
IRQ 0.50 ± 0.11 1.00 ± 0.28 13.21 ± 1.32 0.04 ± 0.01٭ ++
٭p<0.05 vs C, +p<0.05 vs IR, ++p<0.005 vs IR, xxp<0.005 vs QIR, n.d. not detected

Table 3. TBARS. Effect of coenzyme Q10 supplementation on plasma and brain thiobarbituric acid reactive substances (TBARS) formation in rats subjected to transient ischemia-reperfusion injury using three cerebral vessels occlusion (3-VO). Values are expressed in mean (n = 6) ± S.E.M. ٭ = P < 0.05 vs. control group©; + = P < 0.05 vs. ischemia reperfusion group (IR).

  Plasma (μmol.l-1) Brain homogenate(μmol.kg-1)
C 9.18 ± 0.51 94.24 ± 8.14
IR 10.56 ± 0.20٭ 93.16 ± 4.02
QIR 10.08 ± 0.27 104.96 ± 6.71
IRQ 9.71 ± 0.24+  
٭p<0.05 vs C, +p<0.05 vs IR

Effect of coenzyme Q supplementation on ischemia-reperfusion induced impairment of endogenous antioxidants

The concentrations of CoQ and tocopherols in brain mitochondria are presented in Table 2 and in Figure 2. Concentration of oxidized forms CoQ9 (CoQ9 ox) and CoQ10 (CoQ10 ox) in brain mitochondria after ischemia-reperfusion did not differ from control group, and decreased concentrations of α-tocopherol and γ-tocopherol are not significant.

Effect of coenzyme Q10

Figure 2. Effect of coenzyme Q10 (CoQ10) supplementation (200 mg/kg/day) on the concentrations of oxidized form coenzyme Q9-ox, coenzyme Q10-ox, α- and γ- tocopherols in brain mitochondria of rats subjected to transient cerebrovascular ischemia. C, control group; IR, brain ischemia (3-VO) for 50 min followed by reperfusion for 30 days; QIR, preventive CoQ10 supplementation for 30 days before ischemia reperfusion;IRQ, therapeutic CoQ10 supplementation for 30 days after 3-VO for 50 min. Values are expressed as percentage of control group. ٭ = P < 0.05 vs. control group; + = P < 0.05 vs. ischemia-reperfusion group; x= P< 0.05

Similarly, concentration of CoQ9 ox and CoQ10 ox in brain mitochondria after preventive supplementation of CoQ10 for 30 days before ischemia-reperfusion injury did not differ from control group and from ischemia-reperfusion group, and the concentrations of α-tocopherol and γ-tocopherol are not significant.

Therapeutic supplementation of CoQ10 for 30 days after crebrovascular occlusion shows significant increased concentration of CoQ9 ox by 36% (P<0.05), normal values in the concentration of CoQ10 – ox and α-tocopherol, but significant decrease of γ-tocopherol (60%, P<0.05) when compared to control group.

Effect of coenzyme Q10

Figure 3. Effect of coenzyme Q10 (CoQ10) supplementation on plasma concentrations of oxidized forms of coenzyme Q9 (CoQ9-ox), coenzyme Q10 (CoQ10-ox), α- and γ- tocopherols in rats subjected to transient ischemia-reperfusion using three cerebral vessels occlusion (3-VO). C, control group; IR, ischemia for 50 minutes followed by reperfusion for 30 days; QIR, preventive CoQ10 supplementation for 30 days before ischemia-reperfusion; IRQ, therapeutic CoQ10 supplementation for 30 days after 50 min of cerebrovascular occlusion (3-VO). Values are expressed as percentage of control group (n = 6). ٭ = P < 0.05 vs. control group; + = P < 0.05 vs. ischemia-reperfusion group.

Effect of ischemia-reperfusion injury

Figure 4. Effect of ischemia-reperfusion injury and CoQ10 supplementation on brain and plasma thiobarbituric acid reactive substances (TBARS) formation in rats. C, control group; IR, ischemia (50 min)-reperfusion (30 d) group; QIR, preventive CoQ10 supplementation for 30 d before ischemia-reperfusion; IRQ, therapeutic supplementation of CoQ10 for 30 d after ischemia . Values are expressed as percentage of control group. (n = 6) ). ٭ = P < 0.05 vs. control; + = P < 0.05 vs. ischemia-reperfusion.

The effects of CoQ10 supplementation on plasma concentrations of CoQ and tocopherols are presented on Tab. 2. and Fig. 3. Plasma concentration of CoQ9-ox significantly decreased by 59% (P<0.05) after ischemia-reperfusion; decrease of α-tocopherol and increase of γ-tocopherol are not significant when compared with control group.

Preventive supplementation with CoQ10 led to normal concentration of α-tocopherol (P<0.05), but to lower concentration of γ-tocopherol, compared with control and ischemia-reperfusion groups without CoQ10 supplementation. Therapeutic supplementation with CoQ10 keep normal level of α-tocopherol, but the concentration of CoQ9-ox and γ-tocopherol had significantly lower levels (P<0.05). CoQ10-ox concentrations in plasma were not detectable.

Effect of coenzyme Q supplementation on TBARS formation

Plasma and brain values of thiobarbituric acid reactive substance (TBARS) formations as an index of oxidative stress are expressed in Tab. 3. and Fig. 4.

Ischemia-reperfusion produced significant increase in plasma formation of TBARS (P<0.05), but not in brain homogenate. After preventive CoQ10 supplementation the values of TBARS in plasma not differ from values of ischemia-reperfusion group, but in brain homogenate the values of TBARS tended to increase. After therapeutic CoQ10 supplementation the values of TBARS significantly decreased (P<0.05) when compared with ischemia-reperfusion group, and in brain homogenate the values of TBARS not differ from control groups.

Discussion

Normal function of the brain is dependent on adequate blood flow and substrate delivery for production of adenosine three phosphate (ATP) in mitochondria. Impaired delivery of glucose together with a deficient delivery of oxygen as energy substrates for aerobic glycolysis lead to mitochondrial dysfunction, oxidative stress and decreased adenosine three phosphate production [15]. Since brain tissue cannot store oxygen or glucose, energy failure can occur after acute or chronic, local or global ischemia resulting in the ischemic neuronal cell changes [16].

Several studies of ischemia/reperfusion-induced injury to mitochondrial energy-transducing processes have been reported. It is known that the brain damage produced by transient cerebral ischemia develops mainly during the reperfusion [17,18]. Sims & Pulsinelly [19] observed decreases in mitochondrial respiratory activity with 3 h of reperfusion following 30-min ischemia, and Sciamanna et al. [20] observed decrease in mitochondrial respiratory activity during 30-min cerebrovascular occlusion and much more decrease of activity after 5-hour of reperfusion. In the present study, we observed similar decrease in mitochondrial respiratory activity with 30-day of reperfusion and 50-min of ischemia induced by three cerebral vessels (3-VO) occlusion (Tab. 1, Fig. 1).

The mitochondrial disorders could be defined either as disorders due to defects of mitochondrial enzymes, or as disorders characterized by morphological abnormalities of mitochondria [1,21]. Brain is more vulnerable to ROS-induced damage due to its high rate of oxygen consumption, high polyunsaturated lipid content, and relative lack of classic antioxidant enzymes [22,23]. In this study, mitochondrial and plasma levels of thiobarbituric acid reactive substances (TBARS) assay was employed as an index of oxidative stress. Cerebrovascular occlusion (3-VO) for 50 min followed by reperfusion for 30 days produce significant impairment in brain mitochondrial oxidative phosphorylation (P<0.05) and 15% increase in (P<0.05) in formation of thiobarbituric acid reactive substances in plasma as index of lipid peroxidation during ischemia-reperfusion injury of rat brain. These results are in agreement with other studies [24]. The overproduction of ROS can be detoxified by endogenous antioxidants [25,26].

Coenzyme Q (ubiquinone), an electron carrier in the inner mitochondrial membrane, may stabilize the respiratory chain components and act as an endogenous antioxidant.[27,28,29]. The present study was undertaken to test whether oral administration of exogenous coenzyme Q could protect against transient cerebral ischemia-induced mitochondrial damage in the rat brain. Zhang et al. [30,31] showed, that dietary coenzyme Q was taken up only into liver, spleen and plasma, and not into kidney, heart, muscle and brain. The beneficial effects exogenous coenzyme Q supplementation was detected only in subjects whose coenzyme Q levels have been depleted by defective synthesis [32].

Conclusion

The results of our study demonstrated that coenzyme Q supplementation for 30 days before the induction of cerebrovascular occlusion is not effective. However, oral supplementation of coenzyme Q during reperfusion significantly protected rats from reperfusion-induced brain injury. Significantly reduced concentration of coenzyme Q in brain and plasma could be explained by the consumption of coenzyme Q consumption due to scavenging of the rapidly generating ROS due to ischemia-reperfusion injury. These observations suggest that the supplementation of coenzyme Q may be potentially viable agent in the clinical therapy of stroke.

Acknowledgements

Supported by Slovak Grant Agency, Project APVV-21-022004. Disclosure/Conflict of Interest: None to declare.

References

  1. De la Torre JC. Critical threshold cerebral hypoperfusion causes Alzheimer’s disease?Acta Neuropathol 1999; 98:1-8.
  2. Aliev G, Palacios HH, Walrafen B, Lipssid AE, Obrenovich ME, Morales L. Brian mitochondria as a primary target in the development of treatment strategies for Alzheimer disease. Int J Biochem Cell Biol 2009;41:1989-2004
  3. Kogure K, Arai H, Abe K, Nakano M. Free radical damage of the brain following ischemia. Prog Brain Res 1985;63:237-259.
  4. Chan PH. Reactive oxygen radicals in signaling and damage in the ischemic brain. J Cereb Blood Flow Metab 2001; 21:2-14.
  5. Jenkins LW, Povlishock JT, Lewelt W, Miller JD, Becker DP. The role of postischemic recirculation on the development of ischemic neuronal injury following complete cerebral ischemia. Acta Neuropathol 1981;55:205-
  6. Mori T, Asano T, Matsui T, Muramatsu H, Ueda M, Kamiya T, Katayama Y, Abe T. Intraluminal increase of superoxide anion following transient focal cerebral ischemia in rats. Brain Res 1999;816:350-357.
  7. Horecký J, Bačiak L, Vančová O, Wimmerová S, Kašparová S. Effects of transient ischemia on rat brain energy metabolism assessed in vivo by 31P MRS and in vitro by mitochondrial OXPHOS. Biochim Biophys Acta – Bioenergetics 2006;Suppl S:178-179.
  8. Horecký J, Bačiak L, Kašparová S, Pacheco G, Aliev G, Vančová O. Minimally invasive surgical approache for three-vessel occlusion as a model of vascular dementia in the rat – brain bioenergetics assay. J Neurol Sci 2009;283(1-2):178-181.
  9. Sarma JSM, Shigeaki I, Fischer R, Maruyama Y, Weishaar R, Bing RJ. Biochemical and contractile properties of heart muscle after prolonged alcohol administration. J Mol Cell Cardiol 1976;8(12):951-972.
  10. Lowry HO, Rosebrough NJ, Farr AL, Randal RJ. Protein measurement with the folin phenol reagent. J Biol Chem 1951;193:265
  11. Lang JK, Gohil K, Packer L. Simultaneous determination of tocopherols, ubiquinols, and ubiquinones in blood, plasma, tissue homogenates, and subcellular fractions. Anal Biochem 1986;157:106-116.
  12. Kucharska J, Gvozdiakova A, Mizera S, Braunová Z, Schreinerova Z, Schramekova E, Pechan I, Fabian J. Participation of coenzyme Q10 in the rejection development of the transplanted heart: a clinical study. Physiol Res 1998;47:399-404.
  13. Ohkawa H, Ohishi N, Yagi K. Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Anal Biochem 1979;95:351-358.
  14. Janero DR, Burghardt B. Thiobarbituric acid-reactive malondialdehyde formation during superoxide-dependent, iron-catalyzed lipid peroxidation: Influence of peroxidation conditions. Lipids 1989;24:125-131.
  15. Aliev G, Smith MA, de la Torre JC, Perry G. Mitochondria as a primary target for vascular hypoperfusion and oxidative stress in Alzhaimer’s disease. Mitochondrion 2004; (5-6): 649-663.
  16. De la Torre JC, Fortin T, Park GAS Pappas BA, Richard MT. Brain blood flow restoration ‘rescues’ chronically damaged rat CA1 neurons. Brain Res 1993; 623: 6-15-28.
  17. Pulsinelly WA, Brierley JB, Plum F. Temporal profile of neuronal damage in a model of transient forebrain ischemia. Ann Neurol 1982;11: 491-498.
  18. Schmidt-Kastner R, Freund TF. Selective vulnerability of the hippocampus in brain ischemia. Neuroscience 1991; 40: 599-636.
  19. Sims NR, Pulsinelli WA. Altered mitochondrial respiration in selectively vulnerable brain subregions following transient forebrain ischemia in the rat. J Neurochem 1987;49(5):1367-1374
  20. Sciamanna MA, Lee CP. Ischemia/reperfusion-induced injury of forebrain mitochondria and protection by ascorbate. Arch Biochem Biophys 1993;35(2):215-224.
  21. Aliev G, Gasimov E, Obrenovich ME, Fischbach K, Shenk JC, Smith MA, Perry G. Atherosclerotic lesions and mitochondria DNA deletions in brain microvessels: Implication in the pathogenesis of Alzheimer’s disease. Vascular Health and Risk Management 2008;4(3):721-730.
  22. Halliwell B, Gutteridge JMC. Oxygen radicals and the nervous system. Trends Neurosci 1985;8:22-26.
  23. Aliev G, Obrenovich ME, Reddy VP, Shenk JC, Moreira PI, Nunomura A, Zhu X, Smith MA, Perry G. Antioxidant therapy in Alzheimer’s disease: theory and practice. Mini Rev Med Chem 2008;8(13):1395-1406.
  24. Candelairo-Jalil E, Mhadu NH, Al-Dalain SM, Martinez G, Leon OS. The course of oxidative damage in different brain regions following transient cerebral ischemia in gerbils. Neurosci Res 2001;41:233-241.
  25. Frank L, Massaro D. Oxygen toxicity. Am J Med 1980;69:117-126.
  26. Ames BN, Shigenda MK, Hagen TM. Oxidants, antioxidants, and the degenerative diseases of aging. Proc Natl Acad Sci USA 1993;90:7915-7922.
  27. Crane FL, Navas P. The diversity of coenzyme Q function. Molec Aspects Med 1997;18:81-86.
  28. James AM, Smith RA, Murphy MP. Antioxidant and prooxidant properties of mitochondrial Coenzyme Q. Arch Biochem Biophys 2004;423:47-56.
  29. Turunen M, Olsson J, Dallner G. Metabolism and function of coenzyme Q. Biochim Biophys Acta 2004;1660:171-199.
  30. ZhangY, Aberg F, Appelkvist E-L, Dallner G, Ernster L. Uptake of dietary coenzyme Q supplement is limited in rats. J Nutr 1995;125:446-453.
  31. Zhang Y, Turunen M, Appelkvist E-L. Restricted uptake of coenzyme Q is in contrast to unrestricted uptake of α-tocopherol into rat organs and cells. J Nutr 1996;126:2089-2097.
  32. Kwong L, Kamzalov S, Rebrin I, Bayne ACV, Jana CK, Morris P, Forster MJ, Sohal RS. Effects of coenzyme Q10 administration on its tissue concentrations, mitochondrial oxidant generation, and oxidative stress in the rat. Free Radic Biol Med 2002;33:627-638.

Correspondence:
Jaromír Horecký

Slovak Medical University
Surgical Pathophysiology and Tissue Engineering Center
Limbová 12, 833 03 Bratislava, Slovak Republic
E-mail: jaromir.horecky(at)szu.sk

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