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Bailey DM, Davies RG, Rose GA, Lewis MH, Aldayem AA, Twine CP, Awad W, Jubouri M, Mohammed I, Mestres CA, Chen EP, Coselli JS, Williams IM, Bashir M. Myths and methodologies: Cardiopulmonary exercise testing for surgical risk stratification in patients with an abdominal aortic aneurysm; balancing risk over benefit. Exp Physiol 2023; 108:1118-1131. [PMID: 37232485 PMCID: PMC10988440 DOI: 10.1113/ep090816] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 05/03/2023] [Indexed: 05/27/2023]
Abstract
The extent to which patients with an abdominal aortic aneurysm (AAA) should exercise remains unclear, given theoretical concerns over the perceived risk of blood pressure-induced rupture, which is often catastrophic. This is especially pertinent during cardiopulmonary exercise testing, when patients are required to perform incremental exercise to symptom-limited exhaustion for the determination of cardiorespiratory fitness. This multimodal metric is being used increasingly as a complementary diagnostic tool to inform risk stratification and subsequent management of patients undergoing AAA surgery. In this review, we bring together a multidisciplinary group of physiologists, exercise scientists, anaesthetists, radiologists and surgeons to challenge the enduring 'myth' that AAA patients should be fearful of and avoid rigorous exercise. On the contrary, by appraising fundamental vascular mechanobiological forces associated with exercise, in conjunction with 'methodological' recommendations for risk mitigation specific to this patient population, we highlight that the benefits conferred by cardiopulmonary exercise testing and exercise training across the continuum of intensity far outweigh the short-term risks posed by potential AAA rupture.
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Affiliation(s)
- Damian M. Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
| | - Richard G. Davies
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
- Department of AnaestheticsUniversity Hospital of WalesCardiffUK
| | - George A. Rose
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
| | - Michael H. Lewis
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
| | | | | | - Wael Awad
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
- Department of Cardiothoracic SurgeryBart's Heart Centre, St Bartholomew's Hospital, Bart's Health NHS TrustLondonUK
| | | | - Idhrees Mohammed
- Institute of Cardiac and Aortic DisordersSRM Institutes for Medical Science (SIMS Hospital)ChennaiTamil NaduIndia
| | - Carlos A. Mestres
- Department of Cardiac SurgeryUniversity Hospital ZürichZürichSwitzerland
| | - Edward P. Chen
- Division of Cardiovascular and Thoracic SurgeryDuke University Medical CenterDurhamNorth CarolinaUSA
| | - Joseph S. Coselli
- Division of Cardiothoracic Surgery, Michael E. DeBakey Department of SurgeryBaylor College of MedicineHoustonTexasUSA
- The Texas Heart InstituteHoustonTexasUSA
- St Luke's‐Baylor St. Luke's Medical CenterHoustonTexasUSA
| | - Ian M. Williams
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
- Department of Vascular SurgeryUniversity Hospital of WalesCardiffUK
| | - Mohamad Bashir
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesGlamorganUK
- Vascular and Endovascular SurgeryHealth & Education Improvement WalesCardiffUK
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Owens TS, Marley CJ, Calverley TA, Stacey BS, Fall L, Tsukamoto H, Iannetelli A, Filipponi T, Davies B, Jones GL, Hirtz C, Lehmann S, Tuaillon E, Marchi N, Bailey DM. Lower systemic nitric oxide bioactivity, cerebral hypoperfusion and accelerated cognitive decline in formerly concussed retired rugby union players. Exp Physiol 2023; 108:1029-1046. [PMID: 37423736 PMCID: PMC10988504 DOI: 10.1113/ep091195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/12/2023] [Indexed: 07/11/2023]
Abstract
NEW FINDINGS What is the central question of this study? What are the molecular, cerebrovascular and cognitive biomarkers of retired rugby union players with concussion history? What is the main finding and its importance? Retired rugby players compared with matched controls exhibited lower systemic nitric oxide bioavailability accompanied by lower middle cerebral artery velocity and mild cognitive impairment. Retired rugby players are more susceptible to accelerated cognitive decline. ABSTRACT Following retirement from sport, the chronic consequences of prior-recurrent contact are evident and retired rugby union players may be especially prone to accelerated cognitive decline. The present study sought to integrate molecular, cerebrovascular and cognitive biomarkers in retired rugby players with concussion history. Twenty retired rugby players aged 64 ± 5 years with three (interquartile range (IQR), 3) concussions incurred over 22 (IQR, 6) years were compared to 21 sex-, age-, cardiorespiratory fitness- and education-matched controls with no prior concussion history. Concussion symptoms and severity were assessed using the Sport Concussion Assessment Tool. Plasma/serum nitric oxide (NO) metabolites (reductive ozone-based chemiluminescence), neuron specific enolase, glial fibrillary acidic protein and neurofilament light-chain (ELISA and single molecule array) were assessed. Middle cerebral artery blood velocity (MCAv, doppler ultrasound) and reactivity to hyper/hypocapnia (CVR CO 2 hyper ${\mathrm{CVR}}_{{\mathrm{CO}}_{\mathrm{2}}{\mathrm{hyper}}}$ /CVR CO 2 hypo ${\mathrm{CVR}}_{{\mathrm{CO}}_{\mathrm{2}}{\mathrm{hypo}}}$ ) were assessed. Cognition was determined using the Grooved Pegboard Test and Montreal Cognitive Assessment. Players exhibited persistent neurological symptoms of concussion (U = 109(41) , P = 0.007), with increased severity compared to controls (U = 77(41) , P < 0.001). Lower total NO bioactivity (U = 135(41) , P = 0.049) and lower basal MCAv were apparent in players (F2,39 = 9.344, P = 0.004). This was accompanied by mild cognitive impairment (P = 0.020, 95% CI, -3.95 to -0.34), including impaired fine-motor coordination (U = 141(41) , P = 0.021). Retired rugby union players with history of multiple concussions may be characterised by impaired molecular, cerebral haemodynamic and cognitive function compared to non-concussed, non-contact controls.
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Affiliation(s)
- Thomas S. Owens
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesUK
| | - Christopher J. Marley
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesUK
| | - Thomas A. Calverley
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesUK
| | - Benjamin S. Stacey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesUK
| | - Lewis Fall
- Faculty of Computing, Engineering and ScienceUniversity of South WalesUK
| | | | - Angelo Iannetelli
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesUK
| | - Teresa Filipponi
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesUK
| | - Bruce Davies
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesUK
| | - Gareth L. Jones
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesUK
| | - Christophe Hirtz
- LBPC‐PPCUniversity of Montpellier, Institute of Regenerative Medicine‐Biotherapy IRMB, Centre Hospitalier Universitaire de Montpellier, INSERMMontpellierFrance
| | - Sylvain Lehmann
- LBPC‐PPCUniversity of Montpellier, Institute of Regenerative Medicine‐Biotherapy IRMB, Centre Hospitalier Universitaire de Montpellier, INSERMMontpellierFrance
| | - Edouard Tuaillon
- CHU Montpellier, Department of Bacteriology‐VirologyCentre University ofMontpellierFrance
| | - Nicola Marchi
- Cerebrovascular and Glia Research, Department of NeuroscienceInstitute of Functional Genomics (University of Montpellier, CNRS, INSERM)MontpellierFrance
| | - Damian M. Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and EducationUniversity of South WalesUK
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Xu C, Yi T, Tan S, Xu H, Hu Y, Ma J, Xu J. Association of Oral or Intravenous Vitamin C Supplementation with Mortality: A Systematic Review and Meta-Analysis. Nutrients 2023; 15:1848. [PMID: 37111066 PMCID: PMC10146309 DOI: 10.3390/nu15081848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/21/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Mortality is the most clinically serious outcome, and its prevention remains a constant struggle. This study was to assess whether intravenous or oral vitamin C (Vit-C) therapy is related to reduced mortality in adults. Data from Medline, Embase, and the Cochrane Central Register databases were acquired from their inception to 26 October 2022. All randomized controlled trials (RCTs) involving intravenous or oral Vit-C against a placebo or no therapy for mortality were selected. The primary outcome was all-cause mortality. Secondary outcomes were sepsis, COVID-19, cardiac surgery, noncardiac surgery, cancer, and other mortalities. Forty-four trials with 26540 participants were selected. Although a substantial statistical difference was observed in all-cause mortality between the control and the Vit-C-supplemented groups (p = 0.009, RR 0.87, 95% CI 0.78 to 0.97, I2 = 36%), the result was not validated by sequential trial analysis. In the subgroup analysis, mortality was markedly reduced in Vit-C trials with the sepsis patients (p = 0.005, RR 0.74, 95% CI 0.59 to 0.91, I2 = 47%), and this result was confirmed by trial sequential analysis. In addition, a substantial statistical difference was revealed in COVID-19 patient mortality between the Vit-C monotherapy and the control groups (p = 0.03, RR 0.84, 95% CI 0.72 to 0.98, I2 = 0%). However, the trial sequential analysis suggested the need for more trials to confirm its efficacy. Overall, Vit-C monotherapy does decrease the risk of death by sepsis by 26%. To confirm Vit-C is associated with reduced COVID-19 mortality, additional clinical random control trials are required.
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Affiliation(s)
- Chongxi Xu
- Department of Neurosurgery, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Wuhou District, Chengdu 610000, China
| | - Tong Yi
- Department of Neurology, The Second People’s Hospital of Deyang City, No. 340 Minjiang West Road, Deyang 618000, China
| | - Siwen Tan
- Outpatient Department, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Wuhou District, Chengdu 610000, China
| | - Hui Xu
- Department of Neurosurgery, The Second People’s Hospital of Liangshan Yi, Autonomous Prefecture, Liangshan 615000, China
| | - Yu Hu
- Department of Neurosurgery, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Wuhou District, Chengdu 610000, China
| | - Junpeng Ma
- Department of Neurosurgery, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Wuhou District, Chengdu 610000, China
| | - Jianguo Xu
- Department of Neurosurgery, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Wuhou District, Chengdu 610000, China
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Bailey DM, Rose GA, O'Donovan D, Locker D, Appadurai IR, Davies RG, Whiston RJ, Bashir M, Lewis MH, Williams IM. Retroperitoneal Compared to Transperitoneal Approach for Open Abdominal Aortic Aneurysm Repair Is Associated with Reduced Systemic Inflammation and Postoperative Morbidity. AORTA (STAMFORD, CONN.) 2022; 10:225-234. [PMID: 36539114 PMCID: PMC9767756 DOI: 10.1055/s-0042-1749173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND In the United Kingdom, the most common surgical approach for repair of open abdominal aortic aneurysms (AAAs) is transperitoneal (TP). However, retroperitoneal (RP) approach is favored in those with more complex vascular anatomy often requiring a cross-clamp on the aorta superior to the renal arteries. This study compared these approaches in patients matched on all major demographic, comorbid, anatomic, and physiological variables. METHODS Fifty-seven patients (TP: n = 24; RP: n = 33) unsuitable for endovascular aneurysm repair underwent preoperative cardiopulmonary exercise testing prior to open AAA repair. The surgical approach undertaken was dictated by individual surgeon preference. Postoperative mortality, complications, and length of hospital stay (LoS) were recorded. Patients were further stratified according to infrarenal (IR) or suprarenal/supraceliac (SR/SC) surgical clamping. Systemic inflammation (C-reactive protein) and renal function (serum creatinine and estimated glomerular filtration rate) were recorded. RESULTS Twenty-three (96%) of TP patients only required an IR clamp compared with 12 (36%) in the RP group. Postoperative systemic inflammation was lower in RP patients (p = 0.002 vs. TP) and fewer reported pulmonary/gastrointestinal complications whereas renal impairment was more marked in those receiving SR/SC clamps (p < 0.001 vs. IR clamp). RP patients were defined by lower LoS (p = 0.001), while mid-/long-term mortality was low/comparable with TP, resulting in considerable cost savings. CONCLUSION Despite the demands of more complicated vascular anatomy, the clinical and economic benefits highlighted by these findings justify the more routine adoption of the RP approach for complex AAA repair.
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Affiliation(s)
- Damian M. Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom,Address for correspondence Damian Miles Bailey, PhD Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South WalesAlfred Russel Wallace Building, CF37 4ATUnited Kingdom
| | - George A. Rose
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
| | - Daniel O'Donovan
- Department of Anaesthetics, University Hospital of Wales, Cardiff, United Kingdom
| | - Dafydd Locker
- Department of Vascular Surgery, University Hospital of Wales, Cardiff, United Kingdom
| | - Ian R. Appadurai
- Department of Anaesthetics, University Hospital of Wales, Cardiff, United Kingdom
| | - Richard G. Davies
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom,Department of Anaesthetics, University Hospital of Wales, Cardiff, United Kingdom
| | - Richard J. Whiston
- Department of Vascular Surgery, University Hospital of Wales, Cardiff, United Kingdom
| | - Mohamad Bashir
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom,Department of Vascular Surgery, University Hospital of Wales, Cardiff, United Kingdom
| | - Michael H. Lewis
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
| | - Ian M. Williams
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom,Department of Vascular Surgery, University Hospital of Wales, Cardiff, United Kingdom
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Rose GA, Davies RG, Appadurai IR, Williams IM, Bashir M, Berg RMG, Poole DC, Bailey DM. 'Fit for surgery': The relationship between cardiorespiratory fitness and postoperative outcomes. Exp Physiol 2022; 107:787-799. [PMID: 35579479 PMCID: PMC9545112 DOI: 10.1113/ep090156] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/11/2022] [Indexed: 11/21/2022]
Abstract
New Findings What is the topic of this review? The relationships and physiological mechanisms underlying the clinical benefits of cardiorespiratory fitness (CRF) in patients undergoing major intra‐abdominal surgery. What advances does it highlight? Elevated CRF reduces postoperative morbidity/mortality, thus highlighting the importance of CRF as an independent risk factor. The vascular protection afforded by exercise prehabilitation can further improve surgical risk stratification and postoperative outcomes.
Abstract Surgery accounts for 7.7% of all deaths globally and the number of procedures is increasing annually. A patient's ‘fitness for surgery’ describes the ability to tolerate a physiological insult, fundamental to risk assessment and care planning. We have evolved as obligate aerobes that rely on oxygen (O2). Systemic O2 consumption can be measured via cardiopulmonary exercise testing (CPET) providing objective metrics of cardiorespiratory fitness (CRF). Impaired CRF is an independent risk factor for mortality and morbidity. The perioperative period is associated with increased O2 demand, which if not met leads to O2 deficit, the magnitude and duration of which dictates organ failure and ultimately death. CRF is by far the greatest modifiable risk factor, and optimal exercise interventions are currently under investigation in patient prehabilitation programmes. However, current practice demonstrates potential for up to 60% of patients, who undergo preoperative CPET, to have their fitness incorrectly stratified. To optimise this work we must improve the detection of CRF and reduce potential for interpretive error that may misinform risk classification and subsequent patient care, better quantify risk by expressing the power of CRF to predict mortality and morbidity compared to traditional cardiovascular risk factors, and improve patient interventions with the capacity to further enhance vascular adaptation. Thus, a better understanding of CRF, used to determine fitness for surgery, will enable both clinicians and exercise physiologists to further refine patient care and management to improve survival.
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Affiliation(s)
- George A Rose
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK
| | - Richard G Davies
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK.,Department of Anaesthetics, University Hospital of Wales, Cardiff, UK
| | - Ian R Appadurai
- Department of Anaesthetics, University Hospital of Wales, Cardiff, UK
| | - Ian M Williams
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK.,Department of Surgery, University Hospital of Wales, Cardiff, UK
| | - Mohammad Bashir
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK.,Department of Surgery, University Hospital of Wales, Cardiff, UK
| | - Ronan M G Berg
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Physiology and Nuclear Medicine, University Hospital Copenhagen - Rigshospitalet, Copenhagen, Denmark.,Centre for Physical Activity Research, University Hospital Copenhagen - Rigshospitalet, Copenhagen, Denmark
| | - David C Poole
- Departments of Kinesiology, Anatomy and Physiology, Kansas State University, USA
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK
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Efficacy and safety of perioperative vitamin C in patients undergoing noncardiac surgery: a systematic review and meta-analysis of randomised trials. Br J Anaesth 2022; 128:664-678. [DOI: 10.1016/j.bja.2021.11.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 11/18/2022] Open
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Vitamin C and kidney transplantation: Nutritional status, potential efficacy, safety, and interactions. Clin Nutr ESPEN 2021; 41:1-9. [PMID: 33487249 DOI: 10.1016/j.clnesp.2020.12.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 12/18/2020] [Accepted: 12/22/2020] [Indexed: 02/02/2023]
Abstract
BACKGROUND AND AIM There are several observational and interventional studies regarding the advantages of sufficient serum levels of vitamin C and the evaluation of the effects of vitamin C supplementation post kidney transplantation. These studies have been put together to investigate the role of vitamin C post-kidney transplantation and make suggestions for designing future studies based on the use of vitamin C supplements or nutritional interventions among these patients. METHODS This narrative review was done by searching in the Embase, PubMed, and SCOPUS databases. RESULTS The results are presented in several sections as follows; nutritional status, potential protective effects, safety concerns, and medications/laboratory tests interactions of vitamin C. CONCLUSIONS Kidney transplant recipients are prone to vitamin C deficiency, which is related to higher mortality based on several long-term observational studies. Vitamin C supplementation improves endothelial function and creatinine clearance. Vitamin C is considered as a safe supplement, however, side effects such as kidney stones, pro-oxidant effect, hemolysis in patients with glucose-6-phosphate dehydrogenase deficiency, impact on lymphocytic activity, acid-base disturbance, and increased sodium load following its administration have been reported. Interaction of vitamin C and cyclosporine is the most important interaction with post-renal transplant medications. Vitamin C also interferes with creatinine assay using Jaffe and enzymatic methods.
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8
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Khan SA, Bhattacharjee S, Ghani MOA, Walden R, Chen QM. Vitamin C for Cardiac Protection during Percutaneous Coronary Intervention: A Systematic Review of Randomized Controlled Trials. Nutrients 2020; 12:E2199. [PMID: 32718091 PMCID: PMC7468730 DOI: 10.3390/nu12082199] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 07/17/2020] [Accepted: 07/21/2020] [Indexed: 12/28/2022] Open
Abstract
Percutaneous coronary intervention (PCI) is the preferred treatment for acute coronary syndrome (ACS) secondary to atherosclerotic coronary artery disease. This nonsurgical procedure is also used for selective patients with stable angina. Although the procedure is essential for restoring blood flow, reperfusion can increase oxidative stress as a side effect. We address whether intravenous infusion of vitamin C (VC) prior to PCI provides a benefit for cardioprotection. A total of eight randomized controlled trials (RCT) reported in the literature were selected from 371 publications through systematic literature searches in six electronic databases. The data of VC effect on cardiac injury biomarkers and cardiac function were extracted from these trials adding up to a total of 1185 patients. VC administration reduced cardiac injury as measured by troponin and CK-MB elevations, along with increased antioxidant reservoir, reduced reactive oxygen species (ROS) and decreased inflammatory markers. Improvement of the left ventricular ejection fraction (LVEF) and telediastolic left ventricular volume (TLVV) showed a trend but inconclusive association with VC. Intravenous infusion of VC before PCI may serve as an effective method for cardioprotection against reperfusion injury.
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Affiliation(s)
- Sher Ali Khan
- Department of Pharmacy Practice and Science, College of Pharmacy, University of Arizona, 1295 N. Martin Ave, Tucson, AZ 85721, USA; (S.A.K.); (S.B.)
| | - Sandipan Bhattacharjee
- Department of Pharmacy Practice and Science, College of Pharmacy, University of Arizona, 1295 N. Martin Ave, Tucson, AZ 85721, USA; (S.A.K.); (S.B.)
| | | | - Rachel Walden
- Annette and Irwin Eskind Family Biomedical Library, Jean & Alexander Heard Libraries, Vanderbilt University, Nashville, TN 37203, USA;
| | - Qin M. Chen
- Department of Pharmacy Practice and Science, College of Pharmacy, University of Arizona, 1295 N. Martin Ave, Tucson, AZ 85721, USA; (S.A.K.); (S.B.)
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10
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Rose GA, Davies RG, Appadurai IR, Lewis WG, Cho JS, Lewis MH, Williams IM, Bailey DM. Cardiorespiratory fitness is impaired and predicts mid-term postoperative survival in patients with abdominal aortic aneurysm disease. Exp Physiol 2018; 103:1505-1512. [PMID: 30255553 DOI: 10.1113/ep087092] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 09/25/2018] [Indexed: 12/30/2022]
Abstract
NEW FINDINGS What is the central question of this study? To what extent cardiorespiratory fitness is impaired in patients with abdominal aortic aneurysmal (AAA) disease and corresponding implications for postoperative survival requires further investigation. What is the main finding and its importance? Cardiorespiratory fitness is impaired in patients with AAA disease. Patients with peak oxygen uptake of <13.1 ml O2 kg-1 min-1 and ventilatory equivalent for carbon dioxide at anaerobic threshold ≥34 are associated with increased risk of postoperative mortality at 2 years. These findings demonstrate that cardiorespiratory fitness can predict mid-term postoperative survival in AAA patients, which may help to direct care provision. ABSTRACT Preoperative cardiopulmonary exercise testing is a standard assessment of cardiorespiratory fitness (CRF) and risk stratification. However, to what extent CRF is impaired in patients undergoing surgical repair of abdominal aortic aneurysm (AAA) disease and the corresponding implications for postoperative outcome requires further investigation. We measured CRF during an incremental exercise test to exhaustion using online respiratory gas analysis in patients with AAA disease (n = 124, aged 72 ± 7 years) and healthy sedentary control subjects (n = 104, aged 70 ± 7 years). Postoperative survival was examined for association with CRF, and threshold values were calculated for independent predictors of mortality. Patients who underwent preoperative cardiopulmonary exercise testing before surgical repair had lower CRF [age-adjusted mean difference of 12.5 ml O2 kg-1 min-1 for peak oxygen uptake ( V ̇ O 2 peak ), P < 0.001 versus control subjects]. After multivariable analysis, both V ̇ O 2 peak and the ventilatory equivalent for carbon dioxide at anaerobic threshold ( V ̇ E / V ̇ C O 2 - AT ) were independent predictors of mid-term postoperative survival (2 years). Hazard ratios of 5.27 (95% confidence interval 1.62-17.14, P = 0.006) and 3.26 (95% confidence interval 1.00-10.59, P = 0.049) were observed for V ̇ O 2 peak < 13.1 ml O2 kg-1 min-1 and V ̇ E / V ̇ C O 2 - AT ≥ 34, respectively. Thus, CRF is lower in patients with AAA, and those with a V ̇ O 2 peak < 13.1 ml O2 kg-1 min-1 and V ̇ E / V ̇ C O 2 - AT ≥ 34 are associated with a markedly increased risk of postoperative mortality. Collectively, our findings demonstrate that CRF can predict mid-term postoperative survival in AAA patients, which may help to direct care provision.
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Affiliation(s)
- G. A. Rose
- Faculty of Life Sciences and Education; University of South Wales; Pontypridd UK
| | - R. G. Davies
- Department of Anaesthetics; University Hospital of Wales; Cardiff UK
| | - I. R. Appadurai
- Department of Anaesthetics; University Hospital of Wales; Cardiff UK
| | - W. G. Lewis
- Department of Surgery; University Hospital of Wales; Cardiff UK
| | - J. S. Cho
- Department of Cardiovascular Surgery; Kings College London; London UK
| | - M. H. Lewis
- Faculty of Life Sciences and Education; University of South Wales; Pontypridd UK
| | - I. M. Williams
- Department of Surgery; University Hospital of Wales; Cardiff UK
| | - D. M. Bailey
- Faculty of Life Sciences and Education; University of South Wales; Pontypridd UK
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Bailey DM, Rasmussen P, Evans KA, Bohm AM, Zaar M, Nielsen HB, Brassard P, Nordsborg NB, Homann PH, Raven PB, McEneny J, Young IS, McCord JM, Secher NH. Hypoxia compounds exercise-induced free radical formation in humans; partitioning contributions from the cerebral and femoral circulation. Free Radic Biol Med 2018; 124:104-113. [PMID: 29859345 DOI: 10.1016/j.freeradbiomed.2018.05.090] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/19/2018] [Accepted: 05/29/2018] [Indexed: 12/19/2022]
Abstract
This study examined to what extent the human cerebral and femoral circulation contribute to free radical formation during basal and exercise-induced responses to hypoxia. Healthy participants (5♂, 5♀) were randomly assigned single-blinded to normoxic (21% O2) and hypoxic (10% O2) trials with measurements taken at rest and 30 min after cycling at 70% of maximal power output in hypoxia and equivalent relative and absolute intensities in normoxia. Blood was sampled from the brachial artery (a), internal jugular and femoral veins (v) for non-enzymatic antioxidants (HPLC), ascorbate radical (A•-, electron paramagnetic resonance spectroscopy), lipid hydroperoxides (LOOH) and low density lipoprotein (LDL) oxidation (spectrophotometry). Cerebral and femoral venous blood flow was evaluated by transcranial Doppler ultrasound (CBF) and constant infusion thermodilution (FBF). With 3 participants lost to follow up (final n = 4♂, 3♀), hypoxia increased CBF and FBF (P = 0.041 vs. normoxia) with further elevations in FBF during exercise (P = 0.002 vs. rest). Cerebral and femoral ascorbate and α-tocopherol consumption (v < a) was accompanied by A•-/LOOH formation (v > a) and increased LDL oxidation during hypoxia (P < 0.043-0.049 vs. normoxia) implying free radical-mediated lipid peroxidation subsequent to inadequate antioxidant defense. This was pronounced during exercise across the femoral circulation in proportion to the increase in local O2 uptake (r = -0.397 to -0.459, P = 0.037-0.045) but unrelated to any reduction in PO2. These findings highlight considerable regional heterogeneity in the oxidative stress response to hypoxia that may be more attributable to local differences in O2 flux than to O2 tension.
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Affiliation(s)
- Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK.
| | - Peter Rasmussen
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
| | - Kevin A Evans
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
| | - Aske M Bohm
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
| | - Morten Zaar
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
| | - Henning B Nielsen
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, Canada
| | - Nikolai B Nordsborg
- Faculty of Science, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | | | - Peter B Raven
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center, TX, USA
| | - Jane McEneny
- Centre for Public Health, Queen's University Belfast, Northern Ireland, UK
| | - Ian S Young
- Centre for Public Health, Queen's University Belfast, Northern Ireland, UK
| | - Joe M McCord
- Department of Medicine, Division of Pulmonary Science and Critical Care Medicine, University of Colorado at Denver, Denver, CO, USA
| | - Niels H Secher
- Department of Anesthesia, Rigshospitalet, University of Copenhagen, Denmark
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12
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Marley CJ, Sinnott A, Hall JE, Morris-Stiff G, Woodsford PV, Lewis MH, Bailey DM. Failure to account for practice effects leads to clinical misinterpretation of cognitive outcome following carotid endarterectomy. Physiol Rep 2018; 5:5/11/e13264. [PMID: 28611148 PMCID: PMC5471430 DOI: 10.14814/phy2.13264] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 03/31/2017] [Indexed: 11/24/2022] Open
Abstract
Carotid endarterectomy (CEA) is a surgical procedure to remove stenotic atherosclerotic plaque from the origin of the carotid artery to reduce the risk of major stroke. Its impact on postoperative cognitive function (POCF) remains controversial; complicated, in part, by a traditional failure to account for practice effects incurred during consecutive psychometric testing. To address this for the first time, we performed psychometric testing (learning and memory, working memory, attention and information processing, and visuomotor coordination) in 15 male patients aged 68 ± 8 years with symptomatic carotid stenosis the day before and 24 h following elective CEA (two consecutive tests, 48 h apart). Multiple baselining was also performed in a separate cohort of 13 educationally, anthropometrically and age‐matched controls (63 ± 9 years) not undergoing revascularization at identical time points with additional measures performed over a further 96 h (four consecutive tests, each 48 h apart). A single consecutive test in the control group resulted in progressive improvements in learning and memory, working memory, and attention and information (P < 0.05 vs. Test 1), with three tests required before cognitive performance stabilized. Following correction for practice effects in the patient group, CEA was associated with a deterioration rather than an improvement in learning and memory as originally observed (P < 0.05). These findings highlight the potential for the clinical misinterpretation of POCF unless practice effects are taken into account and provide practical recommendations for implementation within the clinical setting.
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Affiliation(s)
- Christopher J Marley
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, United Kingdom
| | - Andrew Sinnott
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, United Kingdom
| | - Judith E Hall
- Department of Anaesthetics and Intensive Care Medicine, Cardiff University, Wales, United Kingdom
| | - Gareth Morris-Stiff
- Department of HPB Surgery, Digestive Disease Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Paul V Woodsford
- Department of Surgery, Royal Glamorgan Hospital, Wales, United Kingdom
| | - Michael H Lewis
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, United Kingdom.,Department of Surgery, Royal Glamorgan Hospital, Wales, United Kingdom
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, United Kingdom .,Faculty of Medicine, Reichwald Health Sciences Centre University of British Columbia-Okanagan, Kelowna, British Columbia, Canada
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Bain AR, Ainslie PN, Hoiland RL, Barak OF, Drvis I, Stembridge M, MacLeod DM, McEneny J, Stacey BS, Tuaillon E, Marchi N, Fayd'Herbe De Maudave A, Dujic Z, MacLeod DB, Bailey DM. Competitive apnea and its effect on the human brain: focus on the redox regulation of blood-brain barrier permeability and neuronal-parenchymal integrity. FASEB J 2018; 32:2305-2314. [PMID: 29191963 DOI: 10.1096/fj.201701031r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Static apnea provides a unique model that combines transient hypertension, hypercapnia, and severe hypoxemia. With apnea durations exceeding 5 min, the purpose of the present study was to determine how that affects cerebral free-radical formation and the corresponding implications for brain structure and function. Measurements were obtained before and following a maximal apnea in 14 divers with transcerebral exchange kinetics, measured as the product of global cerebral blood flow (duplex ultrasound) and radial arterial to internal jugular venous concentration differences ( a-vD). Apnea increased the systemic (arterial) and, to a greater extent, the regional (jugular venous) concentration of the ascorbate free radical, resulting in a shift from net cerebral uptake to output ( P < 0.05). Peroxidation (lipid hydroperoxides, LDL oxidation), NO bioactivity, and S100β were correspondingly enhanced ( P < 0.05), the latter interpreted as minor and not a pathologic disruption of the blood-brain barrier. However, those changes were insufficient to cause neuronal-parenchymal damage confirmed by the lack of change in the a-vD of neuron-specific enolase and human myelin basic protein ( P > 0.05). Collectively, these observations suggest that increased cerebral oxidative stress following prolonged apnea in trained divers may reflect a functional physiologic response, rather than a purely maladaptive phenomenon.-Bain, A. R., Ainslie, P. N., Hoiland, R. L., Barak, O. F., Drvis, I., Stembridge, M., MacLeod, D. M., McEneny, J., Stacey, B. S., Tuaillon, E., Marchi, N., De Maudave, A. F., Dujic, Z., MacLeod, D. B., Bailey, D. M. Competitive apnea and its effect on the human brain: focus on the redox regulation of blood-brain barrier permeability and neuronal-parenchymal integrity.
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Affiliation(s)
- Anthony R Bain
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada
- Integrative Physiology, University of Colorado, Boulder, Colorado, USA
| | - Philip N Ainslie
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada
| | - Ryan L Hoiland
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Science, University of British Columbia, Kelowna, British Columbia, Canada
| | - Otto F Barak
- School of Medicine, University of Split, Split, Croatia
- Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia
| | - Ivan Drvis
- School of Kinesiology, University of Zagreb, Zagreb, Croatia
| | - Mike Stembridge
- Cardiff Centre for Exercise & Health, Cardiff Metropolitan University, Cardiff, United Kingdom
| | | | - Jane McEneny
- Centre for Public Health, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom
| | - Benjamin S Stacey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
| | - Eduoard Tuaillon
- Unit Mixte de Recherche (UMR), INSERM l'Etablissement Français du Sang (EFS), Université Montpellier 1, Montpellier, France
| | - Nicola Marchi
- UMR, Laboratory of Cerebrovascular Mechanisms of Brain Disorders, Department of Neuroscience, Centre National de la Recherche Scientifique (CNRS), INSERM, Institute of Functional Genomics, Montpellier, France; and
| | - Alexis Fayd'Herbe De Maudave
- UMR, Laboratory of Cerebrovascular Mechanisms of Brain Disorders, Department of Neuroscience, Centre National de la Recherche Scientifique (CNRS), INSERM, Institute of Functional Genomics, Montpellier, France; and
| | - Zeljko Dujic
- School of Medicine, University of Split, Split, Croatia
| | - David B MacLeod
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, United Kingdom
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Cadenas S. ROS and redox signaling in myocardial ischemia-reperfusion injury and cardioprotection. Free Radic Biol Med 2018; 117:76-89. [PMID: 29373843 DOI: 10.1016/j.freeradbiomed.2018.01.024] [Citation(s) in RCA: 516] [Impact Index Per Article: 86.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/19/2018] [Accepted: 01/21/2018] [Indexed: 02/06/2023]
Abstract
Ischemia-reperfusion (IR) injury is central to the pathology of major cardiovascular diseases, such as stroke and myocardial infarction. IR injury is mediated by several factors including the elevated production of reactive oxygen species (ROS), which occurs particularly at reperfusion. The mitochondrial respiratory chain and NADPH oxidases of the NOX family are major sources of ROS in cardiomyocytes. The first part of this review discusses recent findings and controversies on the mechanisms of superoxide production by the mitochondrial electron transport chain during IR injury, as well as the contribution of the NOX isoforms expressed in cardiomyocytes, NOX1, NOX2 and NOX4, to this damage. It then focuses on the effects of ROS on the opening of the mitochondrial permeability transition pore (mPTP), an inner membrane non-selective pore that causes irreversible damage to the heart. The second part analyzes the redox mechanisms of cardiomyocyte mitochondrial protection; specifically, the activation of the hypoxia-inducible factor (HIF) pathway and the antioxidant transcription factor Nrf2, which are both regulated by the cellular redox state. Redox mechanisms involved in ischemic preconditioning, one of the most effective ways of protecting the heart against IR injury, are also reviewed. Interestingly, several of these protective pathways converge on the inhibition of mPTP opening during reperfusion. Finally, the clinical and translational implications of these cardioprotective mechanisms are discussed.
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Affiliation(s)
- Susana Cadenas
- Centro de Biología Molecular "Severo Ochoa" (CSIC-UAM) and Departamento de Biología Molecular, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain; Instituto de Investigación Sanitaria Princesa (IIS-IP), 28006 Madrid, Spain.
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15
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Badu-Boateng C, Pardalaki S, Wolf C, Lajnef S, Peyrot F, Naftalin RJ. Labile iron potentiates ascorbate-dependent reduction and mobilization of ferritin iron. Free Radic Biol Med 2017; 108:94-109. [PMID: 28336129 DOI: 10.1016/j.freeradbiomed.2017.03.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 01/29/2017] [Accepted: 03/15/2017] [Indexed: 12/18/2022]
Abstract
Ascorbate mobilizes iron from equine spleen ferritin by two separate processes. Ascorbate alone mobilizes ferritin iron with an apparent Km (ascorbate) ≈1.5mM. Labile iron >2μM, complexed with citrate (10mM), synergises ascorbate-dependent iron mobilization by decreasing the apparent Km (ascorbate) to ≈270μM and raising maximal mobilization rate by ≈5-fold. Catalase reduces the apparent Km(ascorbate) for both ascorbate and ascorbate+iron dependent mobilization by ≈80%. Iron mobilization by ascorbate alone has a higher activation energy (Ea=45.0±5.5kJ/mole) than when mediated by ascorbate with labile iron (10μM) (Ea=13.7±2.2kJ/mole); also mobilization by iron-ascorbate has a three-fold higher pH sensitivity (pH range 6.0-8.0) than with ascorbate alone. Hydrogen peroxide inhibits ascorbate's iron mobilizing action. EPR and autochemiluminescence studies show that ascorbate and labile iron within ferritin enhances radical formation, whereas ascorbate alone produces negligible radicals. These findings suggest that iron catalysed single electron transfer reactions from ascorbate, involving ascorbate or superoxide and possibly ferroxidase tyrosine radicals, accelerate iron mobilization from the ferroxidase centre more than EPR silent, bi-dentate two-electron transfers. These differing modes of electron transference from ascorbate mirror the known mono and bidentate oxidation reactions of dioxygen and hydrogen peroxide with di-ferrous iron at the ferroxidase centre. This study implies that labile iron, at physiological pH, complexed with citrate, synergises iron mobilization from ferritin by ascorbate (50-4000μM). This autocatalytic process can exacerbate oxidative stress in ferritin-containing inflamed tissue.
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Affiliation(s)
- Charles Badu-Boateng
- Cardiovascular Division, British Heart Foundation Centre of Research Excellence and Physiology Department, King's College London, 150 Stamford Street, London SE1 9NH, UK
| | - Sofia Pardalaki
- Cardiovascular Division, British Heart Foundation Centre of Research Excellence and Physiology Department, King's College London, 150 Stamford Street, London SE1 9NH, UK
| | | | - Sonia Lajnef
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques (UMR CNRS 8601), Université Paris Descartes, 75006 Paris, France
| | - Fabienne Peyrot
- Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques (UMR CNRS 8601), Université Paris Descartes, 75006 Paris, France; ESPE de l'académie de Paris, Université Paris Sorbonne, 75016 Paris, France
| | - Richard J Naftalin
- Cardiovascular Division, British Heart Foundation Centre of Research Excellence and Physiology Department, King's College London, 150 Stamford Street, London SE1 9NH, UK.
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Khoury T, Tzukert K, Abel R, Abu Rmeileh A, Levi R, Ilan Y. The gut-kidney axis in chronic renal failure: A new potential target for therapy. Hemodial Int 2016; 21:323-334. [DOI: 10.1111/hdi.12486] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 08/06/2016] [Indexed: 12/26/2022]
Affiliation(s)
- Tawfik Khoury
- Department of Medicine, Gastroenterology and Liver Units; Jerusalem Israel
| | - Keren Tzukert
- Department of Nephrology; Hebrew University-Hadassah Medical Center; Jerusalem Israel
| | - Roy Abel
- Department of Nephrology; Hebrew University-Hadassah Medical Center; Jerusalem Israel
| | - Ayman Abu Rmeileh
- Department of Medicine, Gastroenterology and Liver Units; Jerusalem Israel
| | - Ronen Levi
- Department of Nephrology; Hebrew University-Hadassah Medical Center; Jerusalem Israel
| | - Yaron Ilan
- Department of Medicine, Gastroenterology and Liver Units; Jerusalem Israel
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17
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Bailey DM, Evans TG, Thomas KG, White RD, Twine CP, Lewis MH, Williams IM. Intervisceral artery origins in patients with abdominal aortic aneurysmal disease; evidence for systemic vascular remodelling. Exp Physiol 2016; 101:1143-53. [DOI: 10.1113/ep085804] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Accepted: 05/03/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Damian M. Bailey
- Faculty of Life Sciences and Education; University of South Wales; Pontypridd UK
| | - Tom G. Evans
- Department of Surgery; Royal Glamorgan Hospital; Llantrisant UK
| | | | | | | | - Michael H. Lewis
- Faculty of Life Sciences and Education; University of South Wales; Pontypridd UK
- Department of Surgery; Royal Glamorgan Hospital; Llantrisant UK
| | - Ian M. Williams
- Department of Surgery; University Hospital Wales; Cardiff UK
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18
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Duffy MJ, O'Kane CM, Stevenson M, Young IS, Harkin DW, Mullan BA, McAuley DF. A randomized clinical trial of ascorbic acid in open abdominal aortic aneurysm repair. Intensive Care Med Exp 2015. [PMID: 26215814 PMCID: PMC4486645 DOI: 10.1186/s40635-015-0050-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Background Open AAA repair is associated with ischaemia-reperfusion injury where systemic inflammation and endothelial dysfunction can lead to multiple organ injury including acute lung injury. Oxidative stress plays a role that may be inhibited by ascorbic acid. Methods A double blind, allocation concealed, randomized placebo-controlled trial was performed to test the hypothesis that a single bolus dose (2g) of intra-operative parenteral ascorbic acid would attenuate biomarkers of ischaemia-reperfusion injury in patients undergoing elective open AAA repair. Results Thirty one patients completed the study; 18 received placebo and 13 ascorbic acid. Groups were comparable demographically. Open AAA repair caused an increase in urinary Albumin:Creatinine Ratio (ACR) as well as plasma IL-6 and IL-8. There was a decrease in exhaled breath pH and oxygenation. Lipid hydroperoxides were significantly higher in the ascorbic acid group following open AAA repair. There were no other differences between the ascorbic acid or placebo groups up to 4 hours after removal of the aortic clamping. Conclusions Open AAA repair caused an increase in markers of systemic endothelial damage and systemic inflammation. Administration of 2g parenteral ascorbic acid did not attenuate this response and with higher levels of lipid hydroperoxides post-operatively a pro-oxidant effect could not be excluded. Trial registration ISRCTN27369400
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Affiliation(s)
- Martin J Duffy
- Regional Intensive Care Unit, Royal Victoria Hospital, Belfast, UK,
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19
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Weissig V, Guzman-Villanueva D. Nanocarrier-based antioxidant therapy: promise or delusion? Expert Opin Drug Deliv 2015; 12:1783-90. [DOI: 10.1517/17425247.2015.1063611] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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20
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Tsoi B, Yi RN, Cao LF, Li SB, Tan RR, Chen M, Li XX, Wang C, Li YF, Kurihara H, He RR. Comparing antioxidant capacity of purine alkaloids: A new, efficient trio for screening and discovering potential antioxidants in vitro and in vivo. Food Chem 2015; 176:411-9. [DOI: 10.1016/j.foodchem.2014.12.087] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 07/27/2014] [Accepted: 12/20/2014] [Indexed: 11/16/2022]
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21
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Adam FI, Bounds PL, Kissner R, Koppenol WH. Redox Properties and Activity of Iron–Citrate Complexes: Evidence for Redox Cycling. Chem Res Toxicol 2015; 28:604-14. [DOI: 10.1021/tx500377b] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Fatima I. Adam
- Institute of Inorganic Chemistry,
Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg
1, CH-8093 Zurich, Switzerland
| | - Patricia L. Bounds
- Institute of Inorganic Chemistry,
Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg
1, CH-8093 Zurich, Switzerland
| | - Reinhard Kissner
- Institute of Inorganic Chemistry,
Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg
1, CH-8093 Zurich, Switzerland
| | - Willem H. Koppenol
- Institute of Inorganic Chemistry,
Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg
1, CH-8093 Zurich, Switzerland
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22
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Gastrointestinal Tract Commensal Bacteria and Probiotics: Influence on End-Organ Physiology. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2015; 70:1-33. [PMID: 26462363 DOI: 10.1007/978-3-0348-0927-6_1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Bacteria represent the earliest form of independent life on this planet. Bacterial development has included cooperative symbiosis with plants (e.g., Leguminosae family and nitrogen fixing bacteria in soil) and animals (e.g., the gut microbiome). It is generally agreed upon that the fusion of two prokaryotes evolutionarily gave rise to the eukaryotic cell in which mitochondria may be envisaged as a genetically functional mosaic, a relic from one of the prokaryotes. This is expressed by the appearance of mitochondria in eukaryotic cells (an alpha-proteobacteria input), a significant endosymbiotic evolutionary event. As such, the evolution of human life has been complexly connected to bacterial activities. Hence, microbial colonization of mammals has been a progressively driven process. The interactions between the human host and the microbiome inhabiting the gastrointestinal tract (GIT) for example, afford the human host the necessary cues for the development of regulated signals that in part are induced by reactive oxygen species (ROS). This regulated activity then promotes immunological tolerance and metabolic regulation and stability, which then helps establish control of local and extraintestinal end-organ (e.g., kidneys) physiology. Pharmacobiotics, the targeted administration of live probiotic cultures, is an advancing area of potential therapeutics, either directly or as adjuvants. Hence the continued scientific understanding of the human microbiome in health and disease may further lead to fine tuning the targeted delivery of probiotics for a therapeutic gain.
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23
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Bailey DM, Lundby C, Berg RMG, Taudorf S, Rahmouni H, Gutowski M, Mulholland CW, Sullivan JL, Swenson ER, McEneny J, Young IS, Pedersen BK, Møller K, Pietri S, Culcasi M. On the antioxidant properties of erythropoietin and its association with the oxidative-nitrosative stress response to hypoxia in humans. Acta Physiol (Oxf) 2014; 212:175-87. [PMID: 24811856 DOI: 10.1111/apha.12313] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/14/2014] [Accepted: 05/05/2014] [Indexed: 12/21/2022]
Abstract
AIM The aim of this study was to examine if erythropoietin (EPO) has the potential to act as a biological antioxidant and determine the underlying mechanisms. METHODS The rate at which its recombinant form (rHuEPO) reacts with hydroxyl (HO˙), 2,2-diphenyl-1-picrylhydrazyl (DPPH˙) and peroxyl (ROO˙) radicals was evaluated in-vitro. The relationship between the erythopoietic and oxidative-nitrosative stress response to poikilocapneic hypoxia was determined separately in-vivo by sampling arterial blood from eleven males in normoxia and following 12 h exposure to 13% oxygen. Electron paramagnetic resonance spectroscopy, ELISA and ozone-based chemiluminescence were employed for direct detection of ascorbate (A(˙-) ) and N-tert-butyl-α-phenylnitrone spin-trapped alkoxyl (PBN-OR) radicals, 3-nitrotyrosine (3-NT) and nitrite (NO2-). RESULTS We found rHuEPO to be a potent scavenger of HO˙ (kr = 1.03-1.66 × 10(11) m(-1) s(-1) ) with the capacity to inhibit Fenton chemistry through catalytic iron chelation. Its ability to scavenge DPPH˙ and ROO˙ was also superior compared to other more conventional antioxidants. Hypoxia was associated with a rise in arterial EPO and free radical-mediated reduction in nitric oxide, indicative of oxidative-nitrosative stress. The latter was confirmed by an increased systemic formation of A˙(-) , PBN-OR, 3-NT and corresponding loss of NO2- (P < 0.05 vs. normoxia). The erythropoietic and oxidative-nitrosative stress responses were consistently related (r = -0.52 to 0.68, P < 0.05). CONCLUSION These findings demonstrate that EPO has the capacity to act as a biological antioxidant and provide a mechanistic basis for its reported cytoprotective benefits within the clinical setting.
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Affiliation(s)
- D. M. Bailey
- Neurovascular Research Laboratory; Faculty of Life Sciences and Education; University of South Wales; Treforest UK
- Aix-Marseille Université; CNRS; Institut de Chimie Radicalaire UMR 7273; Équipe Sondes Moleculaires en Biologie et Stress Oxydant; Marseille France
| | - C. Lundby
- Center for Integrative Human Physiology; Institute of Physiology; University of Zurich; Zurich Switzerland
| | - R. M. G. Berg
- Department of Infectious Diseases; Centre of Inflammation and Metabolism; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - S. Taudorf
- Department of Infectious Diseases; Centre of Inflammation and Metabolism; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - H. Rahmouni
- Aix-Marseille Université; CNRS; Institut de Chimie Radicalaire UMR 7273; Équipe Sondes Moleculaires en Biologie et Stress Oxydant; Marseille France
| | - M. Gutowski
- Institute of Biochemistry and Cell Biology; Shanghai Institute for Biological Sciences; Chinese Academy of Sciences; Shanghai China
| | - C. W. Mulholland
- Neurovascular Research Laboratory; Faculty of Life Sciences and Education; University of South Wales; Treforest UK
| | - J. L. Sullivan
- Burnett College of Biomedical Sciences; University of Central Florida; Orlando FL USA
| | - E. R. Swenson
- Division of Pulmonary and Critical Care Medicine; Department of Medicine; University of Washington; Seattle WA USA
| | - J. McEneny
- Centre for Clinical and Population Sciences; Queen's University Belfast; Belfast UK
| | - I. S. Young
- Centre for Clinical and Population Sciences; Queen's University Belfast; Belfast UK
| | - B. K. Pedersen
- Department of Infectious Diseases; Centre of Inflammation and Metabolism; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
| | - K. Møller
- Department of Infectious Diseases; Centre of Inflammation and Metabolism; Rigshospitalet; University of Copenhagen; Copenhagen Denmark
- Department of Neuroanaesthesiology; University Hospital Rigshospitalet; Copenhagen Denmark
| | - S. Pietri
- Aix-Marseille Université; CNRS; Institut de Chimie Radicalaire UMR 7273; Équipe Sondes Moleculaires en Biologie et Stress Oxydant; Marseille France
| | - M. Culcasi
- Aix-Marseille Université; CNRS; Institut de Chimie Radicalaire UMR 7273; Équipe Sondes Moleculaires en Biologie et Stress Oxydant; Marseille France
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24
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Rock E, Fardet A. Les antioxydants des agrumes : action en solitaire ou matricielle? ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s10298-014-0852-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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25
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Vitetta L, Linnane AW, Gobe GC. From the gastrointestinal tract (GIT) to the kidneys: live bacterial cultures (probiotics) mediating reductions of uremic toxin levels via free radical signaling. Toxins (Basel) 2013; 5:2042-57. [PMID: 24212182 PMCID: PMC3847713 DOI: 10.3390/toxins5112042] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 11/04/2013] [Accepted: 11/04/2013] [Indexed: 01/04/2023] Open
Abstract
A host of compounds are retained in the body of uremic patients, as a consequence of progressive renal failure. Hundreds of compounds have been reported to be retention solutes and many have been proven to have adverse biological activity, and recognized as uremic toxins. The major mechanistic overview considered to contribute to uremic toxin overload implicates glucotoxicity, lipotoxicity, hexosamine, increased polyol pathway activity and the accumulation of advanced glycation end-products (AGEs). Until recently, the gastrointestinal tract (GIT) and its associated micro-biometabolome was a neglected factor in chronic disease development. A systematic underestimation has been to undervalue the contribution of GIT dysbiosis (a gut barrier-associated abnormality) whereby low-level pro-inflammatory processes contribute to chronic kidney disease (CKD) development. Gut dysbiosis provides a plausible clue to the origin of systemic uremic toxin loads encountered in clinical practice and may explain the increasing occurrence of CKD. In this review, we further expand a hypothesis that posits that environmentally triggered and maintained microbiome perturbations drive GIT dysbiosis with resultant uremia. These subtle adaptation responses by the GIT microbiome can be significantly influenced by probiotics with specific metabolic properties, thereby reducing uremic toxins in the gut. The benefit translates to a useful clinical treatment approach for patients diagnosed with CKD. Furthermore, the role of reactive oxygen species (ROS) in different anatomical locales is highlighted as a positive process. Production of ROS in the GIT by the epithelial lining and the commensal microbe cohort is a regulated process, leading to the formation of hydrogen peroxide which acts as an essential second messenger required for normal cellular homeostasis and physiological function. Whilst this critical review has focused on end-stage CKD (type 5), our aim was to build a plausible hypothesis for the administration of probiotics with or without prebiotics for the early treatment of kidney disease. We postulate that targeting healthy ROS production in the gut with probiotics may be more beneficial than any systemic antioxidant therapy (that is proposed to nullify ROS) for the prevention of kidney disease progression. The study and understanding of health-promoting probiotic bacteria is in its infancy; it is complex and intellectually and experimentally challenging.
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Affiliation(s)
- Luis Vitetta
- The University of Queensland, School of Medicine, Brisbane, St Lucia QLD 4072, Australia
- Medlab, Sydney, New South Wales, Australia; E-Mail:
- Author to whom correspondence should be addressed; E-Mail:
| | - Anthony W. Linnane
- Medlab, Sydney, New South Wales, Australia; E-Mail:
- Monash University, Melbourne VIC 3800, Australia
| | - Glenda C. Gobe
- Centre for Kidney Disease Research, School of Medicine, Translational Research Institute at Princess Alexandra Hospital, The University of Queensland, Brisbane, St Lucia QLD 4072, Australia; E-Mail:
- Department of Nephrology, Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Brisbane QLD 4102, Australia
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Du J, Cullen JJ, Buettner GR. Ascorbic acid: chemistry, biology and the treatment of cancer. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1826:443-57. [PMID: 22728050 PMCID: PMC3608474 DOI: 10.1016/j.bbcan.2012.06.003] [Citation(s) in RCA: 478] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 06/11/2012] [Accepted: 06/13/2012] [Indexed: 12/14/2022]
Abstract
Since the discovery of vitamin C, the number of its known biological functions is continually expanding. Both the names ascorbic acid and vitamin C reflect its antiscorbutic properties due to its role in the synthesis of collagen in connective tissues. Ascorbate acts as an electron-donor keeping iron in the ferrous state thereby maintaining the full activity of collagen hydroxylases; parallel reactions with a variety of dioxygenases affect the expression of a wide array of genes, for example via the HIF system, as well as via the epigenetic landscape of cells and tissues. In fact, all known physiological and biochemical functions of ascorbate are due to its action as an electron donor. The ability to donate one or two electrons makes AscH(-) an excellent reducing agent and antioxidant. Ascorbate readily undergoes pH-dependent autoxidation producing hydrogen peroxide (H(2)O(2)). In the presence of catalytic metals this oxidation is accelerated. In this review, we show that the chemical and biochemical nature of ascorbate contribute to its antioxidant as well as its prooxidant properties. Recent pharmacokinetic data indicate that intravenous (i.v.) administration of ascorbate bypasses the tight control of the gut producing highly elevated plasma levels; ascorbate at very high levels can act as prodrug to deliver a significant flux of H(2)O(2) to tumors. This new knowledge has rekindled interest and spurred new research into the clinical potential of pharmacological ascorbate. Knowledge and understanding of the mechanisms of action of pharmacological ascorbate bring a rationale to its use to treat disease especially the use of i.v. delivery of pharmacological ascorbate as an adjuvant in the treatment of cancer.
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Affiliation(s)
- Juan Du
- Department of Radiation Oncology, University of Iowa College of Medicine, Iowa City, IA, USA
| | - Joseph J. Cullen
- Department of Radiation Oncology, University of Iowa College of Medicine, Iowa City, IA, USA
- Department of Surgery, University of Iowa College of Medicine, Iowa City, IA, USA
- Holden Comprehensive Cancer Center, USA
- Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Garry R. Buettner
- Department of Radiation Oncology, University of Iowa College of Medicine, Iowa City, IA, USA
- Holden Comprehensive Cancer Center, USA
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Kleikers PWM, Wingler K, Hermans JJR, Diebold I, Altenhöfer S, Radermacher KA, Janssen B, Görlach A, Schmidt HHHW. NADPH oxidases as a source of oxidative stress and molecular target in ischemia/reperfusion injury. J Mol Med (Berl) 2012; 90:1391-406. [PMID: 23090009 DOI: 10.1007/s00109-012-0963-3] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 09/26/2012] [Accepted: 09/28/2012] [Indexed: 02/07/2023]
Abstract
Ischemia/reperfusion injury (IRI) is crucial in the pathology of major cardiovascular diseases, such as stroke and myocardial infarction. Paradoxically, both the lack of oxygen during ischemia and the replenishment of oxygen during reperfusion can cause tissue injury. Clinical outcome is also determined by a third, post-reperfusion phase characterized by tissue remodeling and adaptation. Increased levels of reactive oxygen species (ROS) have been suggested to be key players in all three phases. As a second paradox, ROS seem to play a double-edged role in IRI, with both detrimental and beneficial effects. These Janus-faced effects of ROS may be linked to the different sources of ROS or to the different types of ROS that exist and may also depend on the phase of IRI. With respect to therapeutic implications, an untargeted application of antioxidants may not differentiate between detrimental and beneficial ROS, which might explain why this approach is clinically ineffective in lowering cardiovascular mortality. Under some conditions, antioxidants even appear to be harmful. In this review, we discuss recent breakthroughs regarding a more targeted and promising approach to therapeutically modulate ROS in IRI. We will focus on NADPH oxidases and their catalytic subunits, NOX, as they represent the only known enzyme family with the sole function to produce ROS. Similar to ROS, NADPH oxidases may play a dual role as different NOX isoforms may mediate detrimental or protective processes. Unraveling the precise sequence of events, i.e., determining which role the individual NOX isoforms play in the various phases of IRI, may provide the crucial molecular and mechanistic understanding to finally effectively target oxidative stress.
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Affiliation(s)
- Pamela W M Kleikers
- Vascular Drug Discovery Group, Department of Pharmacology and Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands.
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Abstract
Bacterial bloodstream infection causes septic syndromes that range from systemic inflammatory response syndrome (SIRS) and encephalopathy to severe sepsis and septic shock. Microvascular dysfunction, comprising impaired capillary blood flow and arteriolar responsiveness, precedes multiple organ failure. Vitamin C (ascorbate) levels are low in critically ill patients. The impact of ascorbate administered orally is moderate because of its limited bioavailability. However, intravenous injection of ascorbate raises plasma and tissue concentrations of the vitamin and may decrease morbidity. In animal models of polymicrobial sepsis, intravenous ascorbate injection restores microvascular function and increases survival. The protection of capillary blood flow and arteriolar responsiveness by ascorbate may be mediated by inhibition of oxidative stress, modulation of intracellular signaling pathways, and maintenance of homeostatic levels of nitric oxide. Ascorbate scavenges reactive oxygen species (ROS) and also inhibits the NADPH oxidase that synthesizes superoxide in microvascular endothelial cells. The resulting changes in redox-sensitive signaling pathways may diminish endothelial expression of inducible nitric oxide synthase (iNOS), tissue factor and adhesion molecules. Ascorbate also regulates nitric oxide concentration by releasing nitric oxide from adducts and by acting through tetrahydrobiopterin (BH4) to stimulate endothelial nitric oxide synthase (eNOS). Therefore, it may be possible to improve microvascular function in sepsis by using intravenous vitamin C as an adjunct therapy.
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Affiliation(s)
- John X Wilson
- Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, 14214-8028, USA,
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Köhler HF, Delucca IMS, Sbragia Neto L. Antioxidantes enterais em lesões de isquemia e reperfusão em ratos. Rev Col Bras Cir 2011; 38:422-8. [DOI: 10.1590/s0100-69912011000600010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 05/04/2011] [Indexed: 11/22/2022] Open
Abstract
OBJETIVO: Avaliar o papel do pré-tratamento com antioxidantes dietéticos em um modelo experimental de lesão intestinal de isquemia-reperfusão (I/R) em ratos. MÉTODOS: Noventa ratos Wistar adultos machos foram utilizados. Um segmento intestinal foi isolado baseado em seu pedículo vascular. Uma biópsia controle foi realizada e o pedículo foi seccionado e anastomosado novamente, garantindo um tempo de isquemia de 60 minutos, seguido por reperfusão. Biópsias sequenciais foram realizadas ao término do período isquêmico e a cada 15 minutos, durante a reperfusão. O tratamento consistiu de solução salina ou vitamina C ou vitamina E ou a associação destas. Avaliações quantitativa e qualitativa das biópsias foram realizadas. RESULTADOS: Os grupos tratados com vitamina E isolada ou associada com vitamina C apresentaram uma atenuação estatisticamente significativa da lesão de isquemia-reperfusão, com diminuição da perda de altura dos vilos e menor infiltração neutrofílica ao final do estudo quando comparados ao grupo controle e vitamina C exclusiva. CONCLUSÃO: Neste modelo experimental de isquemia-reperfusão, o pré-tratamento com vitamina E atenuou a lesão de I/R no intestino delgado, demonstrado pela diminuição da perda de altura dos vilos e pela atenuação da infiltração neutrofílica.
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Cepinskas G, Wilson JX. Inflammatory response in microvascular endothelium in sepsis: role of oxidants. J Clin Biochem Nutr 2011; 42:175-84. [PMID: 18545638 PMCID: PMC2386519 DOI: 10.3164/jcbn.2008026] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2007] [Accepted: 01/08/2008] [Indexed: 12/22/2022] Open
Abstract
Sepsis, as a severe systemic inflammatory response to bacterial infection, represents a major clinical problem. It is characterized by the excessive production of reactive oxygen species (ROS) both in the circulation and in the affected organs. The excessive generation of ROS inevitably leads to oxidative stress in the microvasculature and has been implicated as a causative event in a number of pathologies including sepsis. In this review, we focus on the role of oxidative and nitrosative stress during the early onset of sepsis. Changes in microvascular endothelial cells, the cell type that occurs in all organs, are discussed. The mechanisms underlying septic induction of oxidative and nitrosative stresses, the functional consequences of these stresses, and potential adjunct therapies for microvascular dysfunction in sepsis are identified.
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Affiliation(s)
- Gediminas Cepinskas
- Centre for Critical Illness Research, Lawson Health Research Institute, 800 Commissioners Rd. E., London, Ontario, N6A 4G4, Canada
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Abstract
Neuro-oxidative-nitrosative stress may prove the molecular basis underlying brain dysfunction in sepsis. In the current review, we describe how sepsis-induced reactive oxygen and nitrogen species (ROS/RNS) trigger lipid peroxidation chain reactions throughout the cerebrovasculature and surrounding brain parenchyma, due to failure of the local antioxidant systems. ROS/RNS cause structural membrane damage, induce inflammation, and scavenge nitric oxide (NO) to yield peroxynitrite (ONOO(-)). This activates the inducible NO synthase, which further compounds ONOO(-) formation. ROS/RNS cause mitochondrial dysfunction by inhibiting the mitochondrial electron transport chain and uncoupling oxidative phosphorylation, which ultimately leads to neuronal bioenergetic failure. Furthermore, in certain 'at risk' areas of the brain, free radicals may induce neuronal apoptosis. In the present review, we define a role for ROS/RNS-mediated neuronal bioenergetic failure and apoptosis as a primary mechanism underlying sepsis-associated encephalopathy and, in sepsis survivors, permanent cognitive deficits.
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Bailey DM, Dehnert C, Luks AM, Menold E, Castell C, Schendler G, Faoro V, Gutowski M, Evans KA, Taudorf S, James PE, McEneny J, Young IS, Swenson ER, Mairbäurl H, Bärtsch P, Berger MM. High-altitude pulmonary hypertension is associated with a free radical-mediated reduction in pulmonary nitric oxide bioavailability. J Physiol 2010; 588:4837-47. [PMID: 20876202 DOI: 10.1113/jphysiol.2010.194704] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
High altitude (HA)-induced pulmonary hypertension may be due to a free radical-mediated reduction in pulmonary nitric oxide (NO) bioavailability. We hypothesised that the increase in pulmonary artery systolic pressure (PASP) at HA would be associated with a net transpulmonary output of free radicals and corresponding loss of bioactive NO metabolites. Twenty-six mountaineers provided central venous and radial arterial samples at low altitude (LA) and following active ascent to 4559 m (HA). PASP was determined by Doppler echocardiography, pulmonary blood flow by inert gas re-breathing, and vasoactive exchange via the Fick principle. Acute mountain sickness (AMS) and high-altitude pulmonary oedema (HAPE) were diagnosed using clinical questionnaires and chest radiography. Electron paramagnetic resonance spectroscopy, ozone-based chemiluminescence and ELISA were employed for plasma detection of the ascorbate free radical (A(·-)), NO metabolites and 3-nitrotyrosine (3-NT). Fourteen subjects were diagnosed with AMS and three of four HAPE-susceptible subjects developed HAPE. Ascent decreased the arterio-central venous concentration difference (a-cv(D)) resulting in a net transpulmonary loss of ascorbate, α-tocopherol and bioactive NO metabolites (P < 0.05 vs. LA). This was accompanied by an increased a-cv(D) and net output of A(·-) and lipid hydroperoxides (P < 0.05 vs. sea level, SL) that correlated against the rise in PASP (r = 0.56-0.62, P < 0.05) and arterial 3-NT (r = 0.48-0.63, P < 0.05) that was more pronounced in HAPE. These findings suggest that increased PASP and vascular resistance observed at HA are associated with a free radical-mediated reduction in pulmonary NO bioavailability.
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Affiliation(s)
- Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Health, Science and Sport, University of Glamorgan, South Wales, UK.
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Giustarini D, Dalle-Donne I, Tsikas D, Rossi R. Oxidative stress and human diseases: Origin, link, measurement, mechanisms, and biomarkers. Crit Rev Clin Lab Sci 2009; 46:241-81. [DOI: 10.3109/10408360903142326] [Citation(s) in RCA: 305] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Bailey DM, Taudorf S, Berg RMG, Lundby C, McEneny J, Young IS, Evans KA, James PE, Shore A, Hullin DA, McCord JM, Pedersen BK, Möller K. Increased cerebral output of free radicals during hypoxia: implications for acute mountain sickness? Am J Physiol Regul Integr Comp Physiol 2009; 297:R1283-92. [PMID: 19726713 DOI: 10.1152/ajpregu.00366.2009] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This study examined whether hypoxia causes free radical-mediated disruption of the blood-brain barrier (BBB) and impaired cerebral oxidative metabolism and whether this has any bearing on neurological symptoms ascribed to acute mountain sickness (AMS). Ten men provided internal jugular vein and radial artery blood samples during normoxia and 9-h passive exposure to hypoxia (12.9% O(2)). Cerebral blood flow was determined by the Kety-Schmidt technique with net exchange calculated by the Fick principle. AMS and headache were determined with clinically validated questionnaires. Electron paramagnetic resonance spectroscopy and ozone-based chemiluminescence were employed for direct detection of spin-trapped free radicals and nitric oxide metabolites. Neuron-specific enolase (NSE), S100beta, and 3-nitrotyrosine (3-NT) were determined by ELISA. Hypoxia increased the arterio-jugular venous concentration difference (a-v(D)) and net cerebral output of lipid-derived alkoxyl-alkyl free radicals and lipid hydroperoxides (P < 0.05 vs. normoxia) that correlated with the increase in AMS/headache scores (r = -0.50 to -0.90, P < 0.05). This was associated with a reduction in a-v(D) and hence net cerebral uptake of plasma nitrite and increased cerebral output of 3-NT (P < 0.05 vs. normoxia) that also correlated against AMS/headache scores (r = 0.74-0.87, P < 0.05). In contrast, hypoxia did not alter the cerebral exchange of S100beta and both global cerebral oxidative metabolism (cerebral metabolic rate of oxygen) and neuronal integrity (NSE) were preserved (P > 0.05 vs. normoxia). These findings indicate that hypoxia stimulates cerebral oxidative-nitrative stress, which has broader implications for other clinical models of human disease characterized by hypoxemia. This may prove a risk factor for AMS by a mechanism that appears independent of impaired BBB function and cerebral oxidative metabolism.
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Affiliation(s)
- Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Health, Science and Sport, University of Glamorgan, Mid-Glamorgan, United Kingdom.
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Bailey DM, George WO, Gutowski M. Theoretical studies of l-ascorbic acid (vitamin C) and selected oxidised, anionic and free-radical forms. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.theochem.2009.06.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bailey DM, Lawrenson L, McEneny J, Young IS, James PE, Jackson SK, Henry RR, Mathieu-Costello O, McCord JM, Richardson RS. Electron paramagnetic spectroscopic evidence of exercise-induced free radical accumulation in human skeletal muscle. Free Radic Res 2009; 41:182-90. [PMID: 17364944 DOI: 10.1080/10715760601028867] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The present study determined if acute exercise increased free radical formation in human skeletal muscle. Vastus lateralis biopsies were obtained in a randomized balanced order from six males at rest and following single-leg knee extensor exercise performed for 2 min at 50% of maximal work rate (WR(MAX)) and 3 min at 100% WR(MAX). EPR spectroscopy revealed an exercise-induced increase in mitochondrial ubisemiquinone (UQ*-) [0.167 +/- 0.055 vs. rest: 0.106 +/- 0.047 arbitrary units (AU)/g total protein (TP), P < 0.05] and alpha-phenyl-tert-butylnitrone-adducts (112 +/- 41 vs. rest: 29 +/- 9 AU/mg tissue mass, P < 0.05). Intramuscular lipid hydroperoxides also increased (0.320 +/- 0.263 vs. rest: 0.148 +/- 0.071 nmol/mg TP, P < 0.05) despite an uptake of alpha-tocopherol, alpha-carotene and beta-carotene. There were no relationships between mitochondrial volume density and any biomarkers of oxidative stress. These findings provide the first direct evidence for intramuscular free radical accumulation and lipid peroxidation following acute exercise in humans.
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Affiliation(s)
- Damian M Bailey
- Department of Physiology, Faculty of Life Sciences, University of Glamorgan, Pontypridd, UK.
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Davison GW, Ashton T, Davies B, Bailey DM. In vitroelectron paramagnetic resonance characterization of free radicals: Relevance to exercise-induced lipid peroxidation and implications of ascorbate prophylaxis. Free Radic Res 2009; 42:379-86. [DOI: 10.1080/10715760801976618] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Sill JC, Proper JA, Johnson ME, Uhl CB, Katusic ZS. Reactive oxygen species and human platelet GP IIb/IIIa receptor activation. Platelets 2009; 18:613-9. [DOI: 10.1080/09537100701481385] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Harrison FE, May JM. Vitamin C function in the brain: vital role of the ascorbate transporter SVCT2. Free Radic Biol Med 2009; 46:719-30. [PMID: 19162177 PMCID: PMC2649700 DOI: 10.1016/j.freeradbiomed.2008.12.018] [Citation(s) in RCA: 406] [Impact Index Per Article: 27.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 12/29/2008] [Accepted: 12/30/2008] [Indexed: 02/07/2023]
Abstract
Ascorbate (vitamin C) is a vital antioxidant molecule in the brain. However, it also has a number of other important functions, participating as a cofactor in several enzyme reactions, including catecholamine synthesis, collagen production, and regulation of HIF-1 alpha. Ascorbate is transported into the brain and neurons via the sodium-dependent vitamin C transporter 2 (SVCT2), which causes accumulation of ascorbate within cells against a concentration gradient. Dehydroascorbic acid, the oxidized form of ascorbate, is transported via glucose transporters of the GLUT family. Once in cells, it is rapidly reduced to ascorbate. The highest concentrations of ascorbate in the body are found in the brain and in neuroendocrine tissues such as adrenal, although the brain is the most difficult organ to deplete of ascorbate. Combined with regional asymmetry in ascorbate distribution within different brain areas, these facts suggest an important role for ascorbate in the brain. Ascorbate is proposed as a neuromodulator of glutamatergic, dopaminergic, cholinergic, and GABAergic transmission and related behaviors. Neurodegenerative diseases typically involve high levels of oxidative stress and thus ascorbate has been posited to have potential therapeutic roles against ischemic stroke, Alzheimer's disease, Parkinson's disease, and Huntington's disease.
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Affiliation(s)
| | - James M. May
- To whom correspondence should be addressed: Dr. James May, 7465 Medical Research Building IV, Vanderbilt University School of Medicine, Nashville, TN 37232-0475. Tel. (615) 936-1653; Fax: (615) 936-1667. E-mail:
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40
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The Effect of Vitamin C on Ischemia Reperfusion Injury Because of Prolonged Tourniquet Application With Reperfusion Intervals. Ann Plast Surg 2009; 62:194-9. [DOI: 10.1097/sap.0b013e318184ab74] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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41
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Kell DB. Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases. BMC Med Genomics 2009; 2:2. [PMID: 19133145 PMCID: PMC2672098 DOI: 10.1186/1755-8794-2-2] [Citation(s) in RCA: 369] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 01/08/2009] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. REVIEW We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here. CONCLUSION Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.
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Abstract
Circulating levels of vitamin C (ascorbate) are low in patients with sepsis. Parenteral administration of ascorbate raises plasma and tissue concentrations of the vitamin and may decrease morbidity. In animal models of sepsis, intravenous ascorbate injection increases survival and protects several microvascular functions, namely, capillary blood flow, microvascular permeability barrier, and arteriolar responsiveness to vasoconstrictors and vasodilators. The effects of parenteral ascorbate on microvascular function are both rapid and persistent. Ascorbate quickly accumulates in microvascular endothelial cells, scavenges reactive oxygen species, and acts through tetrahydrobiopterin to stimulate nitric oxide production by endothelial nitric oxide synthase. A major reason for the long duration of the improvement in microvascular function is that cells retain high levels of ascorbate, which alter redox-sensitive signaling pathways to diminish septic induction of NADPH oxidase and inducible nitric oxide synthase. These observations are consistent with the hypothesis that microvascular function in sepsis may be improved by parenteral administration of ascorbate as an adjuvant therapy.
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Affiliation(s)
- John X Wilson
- Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY 14214-8028, USA.
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Davison GW, Ashton T, George L, Young IS, McEneny J, Davies B, Jackson SK, Peters JR, Bailey DM. Molecular detection of exercise-induced free radicals following ascorbate prophylaxis in type 1 diabetes mellitus: a randomised controlled trial. Diabetologia 2008; 51:2049-59. [PMID: 18769906 DOI: 10.1007/s00125-008-1101-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 05/30/2008] [Indexed: 10/21/2022]
Abstract
AIMS/HYPOTHESIS Patients with type 1 diabetes mellitus are more susceptible than healthy individuals to exercise-induced oxidative stress and vascular endothelial dysfunction, which has important implications for the progression of disease. Thus, in the present study, we designed a randomised double-blind, placebo-controlled trial to test the original hypothesis that oral prophylaxis with vitamin C attenuates rest and exercise-induced free radical-mediated lipid peroxidation in type 1 diabetes mellitus. METHODS All data were collected from hospitalised diabetic patients. The electron paramagnetic resonance spectroscopic detection of spin-trapped alpha-phenyl-tert-butylnitrone (PBN) adducts was combined with the use of supporting markers of lipid peroxidation and non-enzymatic antioxidants to assess exercise-induced oxidative stress in male patients with type 1 diabetes (HbA(1c) 7.9 +/- 1%, n = 12) and healthy controls (HbA(1c) 4.6 +/- 0.5%, n = 14). Following participant randomisation using numbers in a sealed envelope, venous blood samples were obtained at rest, after a maximal exercise challenge and before and 2 h after oral ingestion of 1 g ascorbate or placebo. Participants and lead investigators were blinded to the administration of either placebo or ascorbate treatments. Primary outcome was the difference in changes in free radicals following ascorbate ingestion. RESULTS Six diabetic patients and seven healthy control participants were randomised to each of the placebo and ascorbate groups. Diabetic patients (n = 12) exhibited an elevated concentration of PBN adducts (p < 0.05 vs healthy, n = 14), which were confirmed as secondary, lipid-derived oxygen-centred alkoxyl (RO.) radicals (a(nitrogen) = 1.37 mT and abeta(hydrogen) = 0.18 mT). Lipid hydroperoxides were also selectively elevated and associated with a depression of retinol and lycopene (p < 0.05 vs healthy). Vitamin C supplementation increased plasma vitamin C concentration to a similar degree in both groups (p < 0.05 vs pre-supplementation) and attenuated the exercise-induced oxidative stress response (p < 0.05 vs healthy). There were no selective treatment differences between groups in the primary outcome variable. CONCLUSIONS/INTERPRETATION These findings are the first to suggest that oral vitamin C supplementation provides an effective prophylaxis against exercise-induced free radical-mediated lipid peroxidation in human diabetic blood. CLINICAL TRIALS REGISTRATION NUMBER ISRCTN96164937.
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Affiliation(s)
- G W Davison
- University of Ulster at Jordanstown, County Antrim, BT37 OQB, UK
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Bailey DM, Evans KA, James PE, McEneny J, Young IS, Fall L, Gutowski M, Kewley E, McCord JM, Møller K, Ainslie PN. Altered free radical metabolism in acute mountain sickness: implications for dynamic cerebral autoregulation and blood-brain barrier function. J Physiol 2008; 587:73-85. [PMID: 18936082 DOI: 10.1113/jphysiol.2008.159855] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We tested the hypothesis that dynamic cerebral autoregulation (CA) and blood-brain barrier (BBB) function would be compromised in acute mountain sickness (AMS) subsequent to a hypoxia-mediated alteration in systemic free radical metabolism. Eighteen male lowlanders were examined in normoxia (21% O(2)) and following 6 h passive exposure to hypoxia (12% O(2)). Blood flow velocity in the middle cerebral artery (MCAv) and mean arterial blood pressure (MAP) were measured for determination of CA following calculation of transfer function analysis and rate of regulation (RoR). Nine subjects developed clinical AMS (AMS+) and were more hypoxaemic relative to subjects without AMS (AMS-). A more marked increase in the venous concentration of the ascorbate radical (A(*-)), lipid hydroperoxides (LOOH) and increased susceptibility of low-density lipoprotein (LDL) to oxidation was observed during hypoxia in AMS+ (P < 0.05 versus AMS-). Despite a general decline in total nitric oxide (NO) in hypoxia (P < 0.05 versus normoxia), the normoxic baseline plasma and red blood cell (RBC) NO metabolite pool was lower in AMS+ with normalization observed during hypoxia (P < 0.05 versus AMS-). CA was selectively impaired in AMS+ as indicated both by an increase in the low-frequency (0.07-0.20 Hz) transfer function gain and decrease in RoR (P < 0.05 versus AMS-). However, there was no evidence for cerebral hyper-perfusion, BBB disruption or neuronal-parenchymal damage as indicated by a lack of change in MCAv, S100beta and neuron-specific enolase. In conclusion, these findings suggest that AMS is associated with altered redox homeostasis and disordered CA independent of barrier disruption.
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Affiliation(s)
- D M Bailey
- Neurovascular Research Laboratory, Faculty of Health, Science and Sport, University of Glamorgan, Mid-Glamorgan, South Wales CF37 1DL, UK.
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Nuclear factor E2-related factor 2-dependent myocardiac cytoprotection against oxidative and electrophilic stress. Cardiovasc Toxicol 2008; 8:71-85. [PMID: 18463988 DOI: 10.1007/s12012-008-9016-0] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2008] [Accepted: 04/11/2008] [Indexed: 02/07/2023]
Abstract
Nuclear factor E2-related factor 2 (Nrf2) is a critical regulator of cytoprotective gene expression. However, the role of this transcription factor in myocardiac cytoprotection against oxidative and electrophilic stress remains unknown. This study was undertaken to investigate if Nrf2 signaling could control the constitutive and inducible expression of antioxidants and phase 2 enzymes in primary cardiomyocytes as well as the susceptibility of these cells to oxidative and electrophilic injury. The basal expression of a series of antioxidants and phase 2 enzymes was significantly lower in cardiomyocytes from Nrf2(-/-) mice than those from wild-type littermates. Incubation of wild-type cardiomyocytes with 3H-1,2-dithiole-3-thione (D3T) led to significant induction of various antioxidants and phase 2 enzymes, including catalase, glutathione, glutathione peroxidase (GPx), glutathione reductase, glutathione S-transferase, NAD(P)H:quinone oxidoreductase 1, and heme oxygenase-1. The inducibility of the above cellular defenses except GPx by D3T was abolished in Nrf2(-/-) cardiomyocytes. As compared to wild-type cells, Nrf2(-/-) cardiomyocytes were much more susceptible to cell injury induced by H(2)O(2), peroxynitrite, and 4-hydroxy-2-nonenal. Treatment of wild-type cardiomyocytes with D3T, which upregulated the cellular defenses, resulted in increased resistance to the above oxidant- and electrophile-induced cell injury, whereas D3T treatment of Nrf2(-/-) cardiomyocytes provided no cytoprotection. This study demonstrates that Nrf2 is an important factor in controlling both constitutive and inducible expression of a wide spectrum of antioxidants and phase 2 enzymes in cardiomyocytes and is responsible for protecting these cells against oxidative and electrophilic stress. These findings also implicate Nrf2 as an important signaling molecule for myocardiac cytoprotection.
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Pleiner J, Schaller G, Mittermayer F, Marsik C, MacAllister RJ, Kapiotis S, Ziegler S, Ferlitsch A, Wolzt M. Intra-arterial vitamin C prevents endothelial dysfunction caused by ischemia-reperfusion. Atherosclerosis 2008; 197:383-91. [PMID: 17645881 DOI: 10.1016/j.atherosclerosis.2007.06.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Revised: 05/25/2007] [Accepted: 06/19/2007] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Ischemia-reperfusion (IR) injury causes tissue injury and endothelial dysfunction. There is evidence that oxidative stress plays an important role. METHODS We tested if IR-induced endothelial dysfunction could be prevented by administration of the antioxidant vitamin C. Twenty-six healthy male subjects and eight male patients with peripheral arterial disease (PAD) were enrolled in this randomised placebo-controlled study. Forearm blood flow (FBF) measurements in response to the vasodilators acetylcholine (ACh; endothelium-dependent agonist) or nitroglycerin (NTG; endothelium-independent) were performed before and after forearm ischemia for 20 min. FBF responses were reassessed during reperfusion with intra-arterial co-administration of 24 mg/min vitamin C or placebo. In six volunteers responses to the NO-synthase inhibitor N-monomethyl-L-arginine (L-NMMA) were also assessed before and after ischemia with and without vitamin C. RESULTS ACh-induced vasodilation was blunted in subjects receiving placebo after reperfusion (p<0.05 versus baseline). Administration of vitamin C completely prevented impaired responsiveness. NTG-induced vasodilation was not affected by reperfusion or vitamin C. This finding was consistent in patients with PAD and impaired endothelial function, where local vitamin C infusion restored FBF reactivity to ACh before and after IR injury (p<0.05 versus baseline). Again, NTG-induced vasodilation was not affected. Blunted L-NMMA responses seen during reperfusion could be completely reversed by vitamin C. CONCLUSIONS Our data indicate that IR-induced vascular injury can be prevented by administration of antioxidants.
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Affiliation(s)
- Johannes Pleiner
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
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Bailey DM, Morris-Stiff G, McCord JM, Lewis MH. Has free radical release across the brain after carotid endarterectomy traditionally been underestimated? Significance of reperfusion hemodynamics. Stroke 2007; 38:1946-8. [PMID: 17463314 DOI: 10.1161/strokeaha.106.475376] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Ischemia-reperfusion is an established paradigm for the induction of neuro-oxidative stress. The present report highlights the limitations associated with the measurement of free radical exchange across the human brain after carotid endarterectomy if reperfusion hemodynamics are not taken into account. Summary of Report- Only 2 human studies have reported local changes in the arterio-jugular bulb venous concentration difference (a-v(diff)) of free radicals during carotid endarterectomy. The authors reported either no change or only a very minor trans-cerebral release during the course of reperfusion, which was unexpected. However, consistent with other surgical models of ischemia-reperfusion, reperfusion would have been expected to increase plasma volume consistent with reflow-hemodilution. This would artifactually dilute the local concentration of free radicals, attenuate the a-v(diff) and thus underestimate the "true" magnitude of cerebral free radical release. CONCLUSIONS After correction for reflow-hemodilution, the cerebral generation of free radicals after carotid endarterectomy is likely to be significantly more pronounced than previously documented in humans.
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Linnane AW, Kios M, Vitetta L. Healthy aging: regulation of the metabolome by cellular redox modulation and prooxidant signaling systems: the essential roles of superoxide anion and hydrogen peroxide. Biogerontology 2007; 8:445-67. [PMID: 17415678 DOI: 10.1007/s10522-007-9096-4] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Accepted: 03/08/2007] [Indexed: 12/31/2022]
Abstract
The production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) has long been proposed as leading to random deleterious modification of macromolecules with an associated progressive development of age associated systemic disease. ROS and RNS formation has been posited as a major contributor to the aging process. On the contrary, this review presents evidence that superoxide anion (and hydrogen peroxide) and nitric oxide (and peroxynitrite) constitute regulated prooxidant second messenger systems, with specific sub-cellular locales of production and are essential for normal metabolome and physiological function. The role of these second messengers in the regulation of the metabolome is discussed in terms of radical formation as an essential contributor to the physiologically normal regulation of sub-cellular bioenergy systems; proteolysis regulation; transcription activation; enzyme activation; mitochondrial DNA changes; redox regulation of metabolism and cell differentiation; the concept that orally administered small molecule antioxidant therapy is a chimera. The formation of superoxide anion/hydrogen peroxide and nitric oxide do not conditionally lead to random macromolecular damage; under normal physiological conditions their production is actually regulated consistent with their second messenger roles.
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Affiliation(s)
- Anthony William Linnane
- Epworth Medical Centre, Centre for Molecular Biology and Medicine, 185-187 Hoddle Street, Richmond, Melbourne, VIC 3121, Australia.
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Nakamoto H, Kaneko T, Tahara S, Hayashi E, Naito H, Radak Z, Goto S. Regular exercise reduces 8-oxodG in the nuclear and mitochondrial DNA and modulates the DNA repair activity in the liver of old rats. Exp Gerontol 2007; 42:287-95. [PMID: 17204389 DOI: 10.1016/j.exger.2006.11.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Revised: 11/08/2006] [Accepted: 11/14/2006] [Indexed: 01/09/2023]
Abstract
Exercise is often said to increase the generation of reactive oxygen species that are potentially harmful. On the other hand, regular exercise has various health benefits even late in life. The specific aim of this study was to explore effects of regular exercise on oxidative status of DNA in aged animals. We report that 2 months of regular treadmill running of aged rats (21 month old) significantly reduced 8-oxodG content to the level of young adult animals (11 month old) in both nuclear and mitochondrial DNA of the liver. The mitochondrial DNA showed 10-fold higher content of the oxidative lesion than the nuclear DNA. The levels in old animals were 2- and 1.5-fold higher than that in young adults for the nucleus and mitochondria, respectively. The activity of the repair enzyme OGG1 was upregulated significantly in the nucleus but not in mitochondria by the exercise. To our knowledge, this is the first report demonstrating that regular exercise can reduce significantly oxidative damage to both the nuclear and mitochondrial DNA. We suggest that the apparent beneficial outcomes in reducing the DNA damage by regular exercise can be interpreted in terms of hormetic effect by moderate oxidative stress and potential adaptation to stronger stresses.
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Affiliation(s)
- Hideko Nakamoto
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510, Japan
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Linnane AW, Kios M, Vitetta L. Coenzyme Q(10)--its role as a prooxidant in the formation of superoxide anion/hydrogen peroxide and the regulation of the metabolome. Mitochondrion 2007; 7 Suppl:S51-61. [PMID: 17482887 DOI: 10.1016/j.mito.2007.03.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Revised: 03/16/2007] [Accepted: 03/20/2007] [Indexed: 01/22/2023]
Abstract
Coenzyme Q10 plays a central role in cellular bioenergy generation and its regulation. Closed membrane systems generate a proton motive force to create transient localized bio-capacitors; the captured energy is used for the synthesis of mitochondrial ATP but also for many other processes, such as metabolite translocations, nerve conduction and a host of other bioenergy requiring processes. Coenzyme Q10 plays a key role in many of these sub-cellular membrane energy generating systems. Integral to this phenomenon is the prooxidant role of coenzyme Q10 in generating the major superoxide anion/hydrogen peroxide second messenger system. This messenger system, largely but not exclusively, arises from coenzyme Q10 semiquinone function; it contributes to the regulation of sub-cellular redox potential levels; transcription/gene expression control; is essential for modulated protein turnover and activation; mediates hormone and growth factor extracellular signaling. The regulated prooxidant formation of the superoxide anion/H2O2 second messenger system is essential for the normal physiological function of the metabolome. The normally functioning metabolome is the expression of a finely tuned dynamic equilibrium comprised of thousands of anabolic and catabolic reactions and all cellular signaling systems must be finely regulated. There is still much to be learnt about the up/down regulation of the H2O2 messenger system. The concept that superoxide anion/H2O2 cause random macromolecular damage is rebutted. The administration of antioxidants to quench the inferred toxicity of these compounds as a therapy for age associated diseases is unsupported by extant mammalian clinical trials and should be subject to serious re-evaluation. The role of ascorbic acid as a beneficial hydrogen peroxide prodrug is discussed.
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Affiliation(s)
- Anthony W Linnane
- Centre for Molecular Biology and Medicine, Epworth Medical Centre, 185-187 Hoddle Street, Richmond, Melbourne, Vic. 3121, Australia.
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