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He JD, Parker JD. The effect of vitamin C on nitroglycerin-mediated vasodilation in individuals with and without the aldehyde dehydrogenase 2 polymorphism. Br J Clin Pharmacol 2023; 89:2767-2774. [PMID: 37101414 DOI: 10.1111/bcp.15755] [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: 02/01/2023] [Revised: 04/10/2023] [Accepted: 04/12/2023] [Indexed: 04/28/2023] Open
Abstract
AIMS To mediate its pharmacodynamic effects, glyceryl trinitrate (GTN) requires bioactivation, by which it releases nitric oxide or a nitric oxide moiety. The exact mechanism of GTN bioactivation remains uncertain. Mitochondrial aldehyde dehydrogenase (ALDH-2) has been proposed as the primary enzyme responsible for this bioactivation process. Evidence for the importance of ALDH-2 in GTN bioactivation has been inconsistent, particularly in human models. An alternative hypothesis suggests that decreased ALDH-2 activity leads to accumulation of reactive cytotoxic aldehydes, which either inhibit the vasoactive product(s) of GTN or impair other enzymatic pathways involved in the bioactivation of GTN. We investigated the effect of supplemental vitamin C on vascular responses to GTN in healthy volunteers of East Asian descent, of whom 12 with and 12 without the ALDH-2 polymorphism participated. METHODS Subjects underwent 2 sequential brachial artery infusions of GTN at rates of 5, 11 and 22 nmol/min, separated by a 30-min washout period. The GTN infusions were carried out in the presence and absence of vitamin C using a randomized, crossover design. Venous occlusion plethysmography was used to measure forearm blood flow responses to GTN. RESULTS Compared to subjects with functional ALDH-2, the variant group exhibited blunted hemodynamic responses to intra-arterial GTN infusions, although this reduction in response was not statically significant. Contrary to our hypothesis, vitamin C had an inhibitory effect on GTN mediated vasodilation as compared to GTN during saline in both groups. CONCLUSION We conclude that vitamin C did not augment the acute vascular response to GTN in those with the ALDH-2 polymorphism.
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Affiliation(s)
- Jerry D He
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada
| | - John D Parker
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada
- Division of Cardiology, Department of Medicine, Sinai Health System and the Peter Munk Cardiac Centre, University Health Network, Toronto, Canada
- The Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada
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Volino-Souza M, Oliveira GVD, Tavares AC, Souza K, Alvares T. The effect of microencapsulated watermelon rind ( Citrullus lanatus) and beetroot ( Beta vulgaris L.) ingestion on ischemia/reperfusion-induced endothelial dysfunction: a randomised clinical trial. Food Funct 2023; 14:7959-7968. [PMID: 37561087 DOI: 10.1039/d3fo02612d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Endothelial dysfunction is commonly associated with a cardiovascular event, such as myocardial infarction. Myocardial infarction is marked by an ischemia/reperfusion (IR) phenomenon associated with endothelial dysfunction, contributing even more to future cardiovascular events. Although the supplementation with L-citrulline and nitrate from watermelon and beetroot have been used to improve vascular function, the effect of microencapsulated watermelon rind (WR) or its co-ingestion with beetroot (WR + B) on endothelial IR injury has not been addressed. Therefore, this study aimed to investigate the effect of a single dose of WR and WR + B on IR-induced macro-and microvascular dysfunction. In a randomized, crossover, placebo-controlled study, 12 volunteers underwent macro (flow-mediated dilation) and microvascular (muscle oxygen saturation) assessment and blood collection (to measure L-citrulline, L-arginine, nitrate and nitrite) before and after 20 min of blood occlusion in WR, WR + B and placebo conditions. Prolonged ischemia induced endothelial dysfunction in the macro but not in the microvasculature. The WR and WR + B supplementation significantly restored FMD after IR injury compared to the placebo (p < 0.05). However, there was no significant difference between WR and WR + B in the macrovascular function (p > 0.05). Plasma L-citrulline, L-arginine, nitrate, and nitrite significantly increased (p > 0.05) after WR and WR + B supplementation compared to the placebo. A single dose of WR and WR + B effectively minimizes IR-induced macrovascular endothelial dysfunction in healthy individuals. Beetroot co-ingestion with watermelon did not provide an additional effect of endothelial dysfunction induced by IR (NCT04781595, March 4, 2021).
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Affiliation(s)
- Mônica Volino-Souza
- Nutrition and Exercise Metabolism Research Group, Multidisciplinary Center UFRJ-Macaé, Federal University of Rio de Janeiro, Macaé, Rio de Janeiro, Brazil.
- Postgraduate Program in Food Science, Chemistry Institute, Federal University of Rio de Janeiro, RJ, Brazil
| | - Gustavo Vieira de Oliveira
- Nutrition and Exercise Metabolism Research Group, Multidisciplinary Center UFRJ-Macaé, Federal University of Rio de Janeiro, Macaé, Rio de Janeiro, Brazil.
- Medical Science Institute, Multidisciplinary Center UFRJ-Macaé, Federal University of Rio de Janeiro, Macaé, Brazil
| | - Anna Carolina Tavares
- Nutrition and Exercise Metabolism Research Group, Multidisciplinary Center UFRJ-Macaé, Federal University of Rio de Janeiro, Macaé, Rio de Janeiro, Brazil.
- Food and Nutrition Institute, Multidisciplinary Center UFRJ-Macaé, Federal University of Rio de Janeiro, Macaé, Brazil
| | - Karen Souza
- Nutrition and Exercise Metabolism Research Group, Multidisciplinary Center UFRJ-Macaé, Federal University of Rio de Janeiro, Macaé, Rio de Janeiro, Brazil.
- Food and Nutrition Institute, Multidisciplinary Center UFRJ-Macaé, Federal University of Rio de Janeiro, Macaé, Brazil
| | - Thiago Alvares
- Nutrition and Exercise Metabolism Research Group, Multidisciplinary Center UFRJ-Macaé, Federal University of Rio de Janeiro, Macaé, Rio de Janeiro, Brazil.
- Food and Nutrition Institute, Multidisciplinary Center UFRJ-Macaé, Federal University of Rio de Janeiro, Macaé, Brazil
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Hemingway HW, Richey RE, Moore AM, Olivencia-Yurvati AH, Kline GP, Romero SA. Acute heat exposure protects against endothelial ischemia-reperfusion injury in aged humans. Am J Physiol Regul Integr Comp Physiol 2022; 322:R360-R367. [PMID: 35200050 PMCID: PMC8993535 DOI: 10.1152/ajpregu.00336.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 02/22/2022] [Accepted: 02/22/2022] [Indexed: 11/22/2022]
Abstract
Nonpharmacological therapies that protect against endothelial ischemia-reperfusion injury (I/R) remain limited in aged adults. Acute heat exposure protects against endothelial I/R injury in young adults, but its efficacy has never been explored in aged adults. Therefore, we tested the hypothesis that acute heat exposure would prevent the attenuation of endothelium-dependent vasodilation after I/R injury in aged adults. Nine (2 men, 69 ± 8 yr) aged adults were exposed to a thermoneutral control condition or whole body passive heating (water-perfused suit) sufficient to increase body core temperature by 1.2°C. Experiments were separated by at least 7 days. Heat exposure was always performed first to time match the thermoneutral control condition. Endothelium-dependent vasodilation was assessed via flow-mediated dilation of the brachial artery before (pre-I/R) and after I/R injury (post-I/R), which was induced by 20 min of arm ischemia followed by 20 min of reperfusion. Flow-mediated dilation was reduced following I/R injury for the thermoneutral control condition (pre-I/R, 4.5 ± 2.9% vs. post-I/R, 0.9 ± 2.8%, P < 0.01), but was well maintained with prior heat exposure (pre-I/R, 4.4 ± 2.8% vs. post-I/R, 3.5 ± 2.8%, P = 0.5). Taken together, acute heat exposure protects against endothelial I/R injury in aged adults. These results highlight the therapeutic potential of heat therapy to prevent endothelial dysfunction associated with I/R injury in aged adults who are most at risk for an ischemic event.
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Affiliation(s)
- Holden W Hemingway
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Rauchelle E Richey
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Amy M Moore
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Albert H Olivencia-Yurvati
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
- Department of Surgery, University of North Texas Health Science Center, Fort Worth, Texas
| | - Geoffrey P Kline
- Department of Internal Medicine and Geriatrics, University of North Texas Health Science Center, Fort Worth, Texas
| | - Steven A Romero
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
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Hemingway HW, Richey RE, Moore AM, Shokraeifard AM, Thomas GC, Olivencia-Yurvati AH, Romero SA. Shear stress induced by acute heat exposure is not obligatory to protect against endothelial ischemia-reperfusion injury in humans. J Appl Physiol (1985) 2022; 132:199-208. [PMID: 34941435 PMCID: PMC8759960 DOI: 10.1152/japplphysiol.00748.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Acute heat exposure protects against endothelial ischemia-reperfusion (I/R) injury in humans. However, the mechanism/s mediating this protective effect remain unclear. We tested the hypothesis that inhibiting the increase in shear stress induced by acute heat exposure would attenuate the protection of endothelial function following I/R injury. Nine (3 women) young healthy participants were studied under three experimental conditions: 1) thermoneutral control; 2) whole body heat exposure to increase body core temperature by 1.2°C; and 3) heat exposure + brachial artery compression to inhibit the temperature-dependent increase in shear stress. Endothelial function was assessed via brachial artery flow-mediated dilatation before (pre-I/R) and after (post-I/R) 20 min of arm ischemia followed by 20 min of reperfusion. Brachial artery shear rate was increased during heat exposure (681 ± 359 s-1), but not for thermoneutral control (140 ± 63 s-1; P < 0.01 vs. heat exposure) nor for heat + brachial artery compression (139 ± 60 s-1; P < 0.01 vs. heat exposure). Ischemia-reperfusion injury reduced flow-mediated dilatation following thermoneutral control (pre-I/R, 5.5 ± 2.9% vs. post-I/R, 3.8 ± 2.9%; P = 0.06), but was protected following heat exposure (pre-I/R, 5.8 ± 2.9% vs. post-I/R, 6.1 ± 2.9%; P = 0.5) and heat + arterial compression (pre-I/R, 4.4 ± 2.8% vs. post-I/R, 5.8 ± 2.8%; P = 0.1). Contrary to our hypothesis, our findings demonstrate that shear stress induced by acute heat exposure is not obligatory to protect against endothelial I/R injury in humans.NEW & NOTEWORTHY Acute heat exposure protects against endothelial ischemia-reperfusion injury in humans. However, the mechanism/s mediating this protective effect remain unclear. We utilized arterial compression to inhibit the temperature-dependent increase in brachial artery blood velocity that occurs during acute heat exposure to isolate the contribution of shear stress to the protection of endothelial function following ischemia-reperfusion injury. Our findings demonstrate that shear stress induced by acute heat exposure is not obligatory to protect against endothelial I/R injury.
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Affiliation(s)
- Holden W. Hemingway
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Rauchelle E. Richey
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Amy M. Moore
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Austin M. Shokraeifard
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Gabriel C. Thomas
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Albert H. Olivencia-Yurvati
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas,2Department of Surgery, University of North Texas Health Science Center, Fort Worth, Texas
| | - Steven A. Romero
- 1Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
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Mauerhofer C, Grumet L, Schemmer P, Leber B, Stiegler P. Combating Ischemia-Reperfusion Injury with Micronutrients and Natural Compounds during Solid Organ Transplantation: Data of Clinical Trials and Lessons of Preclinical Findings. Int J Mol Sci 2021; 22:ijms221910675. [PMID: 34639016 PMCID: PMC8508760 DOI: 10.3390/ijms221910675] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/22/2021] [Accepted: 09/26/2021] [Indexed: 02/07/2023] Open
Abstract
Although extended donor criteria grafts bear a higher risk of complications such as graft dysfunction, the exceeding demand requires to extent the pool of potential donors. The risk of complications is highly associated with ischemia-reperfusion injury, a condition characterized by high loads of oxidative stress exceeding antioxidative defense mechanisms. The antioxidative properties, along with other beneficial effects like anti-inflammatory, antiapoptotic or antiarrhythmic effects of several micronutrients and natural compounds, have recently emerged increasing research interest resulting in various preclinical and clinical studies. Preclinical studies reported about ameliorated oxidative stress and inflammatory status, resulting in improved graft survival. Although the majority of clinical studies confirmed these results, reporting about improved recovery and superior organ function, others failed to do so. Yet, only a limited number of micronutrients and natural compounds have been investigated in a (large) clinical trial. Despite some ambiguous clinical results and modest clinical data availability, the vast majority of convincing animal and in vitro data, along with low cost and easy availability, encourage the conductance of future clinical trials. These should implement insights gained from animal data.
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Affiliation(s)
- Christina Mauerhofer
- Department of Science and Product Development, pro medico HandelsGmbH, Liebenauer Tangente 6, 8041 Graz, Austria; (C.M.); (L.G.)
| | - Lukas Grumet
- Department of Science and Product Development, pro medico HandelsGmbH, Liebenauer Tangente 6, 8041 Graz, Austria; (C.M.); (L.G.)
| | - Peter Schemmer
- Division of Transplant Surgery, Department of Surgery, Medical University, 8036 Graz, Austria; (P.S.); (B.L.)
| | - Bettina Leber
- Division of Transplant Surgery, Department of Surgery, Medical University, 8036 Graz, Austria; (P.S.); (B.L.)
| | - Philipp Stiegler
- Division of Transplant Surgery, Department of Surgery, Medical University, 8036 Graz, Austria; (P.S.); (B.L.)
- Correspondence: (P.S.)
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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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7
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Hemingway HW, Moore AM, Olivencia-Yurvati AH, Romero SA. Effect of endoplasmic reticulum stress on endothelial ischemia-reperfusion injury in humans. Am J Physiol Regul Integr Comp Physiol 2020; 319:R666-R672. [PMID: 33074709 DOI: 10.1152/ajpregu.00257.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Endoplasmic reticulum stress contributes to ischemia-reperfusion (I/R) injury in rodent and cell models. However, the contribution of endoplasmic reticulum stress in the pathogenesis of endothelial I/R injury in humans is unknown. We tested the hypothesis that compared with placebo, inhibition of endoplasmic reticulum stress via ingestion of tauroursodeoxycholic acid would prevent the attenuation of endothelium-dependent vasodilation following I/R injury. Twelve young adults (6 women) were studied following ingestion of a placebo or 1,500 mg tauroursodeoxycholic acid (TUDCA). Endothelium-dependent vasodilation was assessed via brachial artery flow-mediated dilation (duplex ultrasonography) before and after I/R injury, which was induced by 20 min of arm ischemia followed by 20 min of reperfusion. Endothelium-independent vasodilation (glyceryl trinitrate-mediated vasodilation) was also assessed after I/R injury. Compared with placebo, TUDCA ingestion increased circulating plasma concentrations by 145 ± 90 ng/ml and increased concentrations of the taurine unconjugated form, ursodeoxycholic acid, by 560 ± 156 ng/ml (both P < 0.01). Ischemia-reperfusion injury attenuated endothelium-dependent vasodilation, an effect that did not differ between placebo (pre-I/R, 5.0 ± 2.1% vs. post-I/R, 3.5 ± 2.2%) and TUDCA (pre-I/R, 5.6 ± 2.1% vs. post-I/R, 3.9 ± 2.1%; P = 0.8) conditions. Similarly, endothelium-independent vasodilation did not differ between conditions (placebo, 19.6 ± 4.8% vs. TUDCA, 19.7 ± 6.1%; P = 0.9). Taken together, endoplasmic reticulum stress does not appear to contribute to endothelial I/R injury in healthy young adults.
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Affiliation(s)
- Holden W Hemingway
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Amy M Moore
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
| | - Albert H Olivencia-Yurvati
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas.,Department of Surgery, University of North Texas Health Science Center, Fort Worth, Texas
| | - Steven A Romero
- Human Vascular Physiology Laboratory, Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas
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Soares RN, Proctor DN, de Oliveira GV, Alvares TS, Murias JM. Acute application of a transdermal nitroglycerin patch protects against prolonged forearm ischemia-induced microvascular dysfunction. Microcirculation 2019; 27:e12599. [PMID: 31782855 DOI: 10.1111/micc.12599] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/13/2019] [Accepted: 11/25/2019] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Prolonged limb blood flow occlusion (ie, tourniquet application during limb surgery) causes transient microvascular dysfunction. We examined the ability of a local nitric oxide donor (transdermal nitroglycerin) administered during prolonged cuff forearm occlusion to protect against microvascular dysfunction and to alter brachial artery dilation. METHODS Ten healthy men (28 ± 8 years) participated in the study. During the control visit, they completed three vascular occlusion tests in the right arm termed, PRE (5-min occlusion), POSTimmediate (20-min occlusion), and POST30min (5-min occlusion). During the nitroglycerin visit, subjects completed the same vascular occlusion tests, but with a nitroglycerin patch placed over the contralateral forearm during the 20-min occlusion test. Micro- and macrovascular function were assessed using the near-infrared spectroscopy-derived reperfusion upslope (reperfusion slope, %.s-1 ) and flow-mediated dilation (%FMD), respectively. RESULTS The reperfusion slope (1.44 ± 0.72%.s-1 ) and the %FMD (15.0 ± 2.8%) of the POSTimmediate test of the nitroglycerin condition were significantly (P < .05) higher than the reperfusion slope (1.01 ± 0.37%.s-1 ) and %FMD (6.77 ± 1.8%) during the POSTimmediate test of the control visit. CONCLUSION Transdermal nitroglycerin protects against ischemia-induced microvascular dysfunction and causes marked dilation of the brachial artery %FMD.
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Affiliation(s)
- Rogerio N Soares
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - David N Proctor
- Department of Kinesiology, Noll Laboratory, Penn State University, University Park, PA, USA
| | | | | | - Juan M Murias
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
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Soares RN, Somani YB, Al-Qahtani AM, Proctor DN, Murias JM. Near-infrared spectroscopy detects transient decrements and recovery of microvascular responsiveness following prolonged forearm ischemia. Microvasc Res 2019; 125:103879. [DOI: 10.1016/j.mvr.2019.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 03/01/2019] [Accepted: 04/29/2019] [Indexed: 10/26/2022]
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Rasheed M, Simmons G, Fisher B, Leslie K, Reed J, Roberts C, Natarajan R, Fowler A, Toor A. Reduced plasma ascorbic acid levels in recipients of myeloablative conditioning and hematopoietic cell transplantation. Eur J Haematol 2019; 103:329-334. [PMID: 31267566 DOI: 10.1111/ejh.13287] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 06/22/2019] [Accepted: 06/25/2019] [Indexed: 12/11/2022]
Abstract
Hematopoietic cell transplantation (HCT) conditioned using myeloablative conditioning (MAC) is complicated by end organ injury due to endothelial dysfunction and graft versus host disease. Mucositis and oxidant injury results in micronutrient deficiency. Ascorbic acid (AA) levels were measured in 15 patients undergoing HCT conditioned with MAC (11 allogeneic and four autologous HCT). Ascorbate levels declined postconditioning to 27.3 μMol/L (±14.1) by day 0 (P = .03 compared with pretransplant baseline), reaching a nadir level of 21.5 (±13.8) on day 14 (P = .003) post-transplant. Patients undergoing allogeneic HCT continued to have low AA levels to day 60 post-transplant. The role of AA in maintaining endothelial function and hematopoietic as well as T-cell recovery is provided, developing the rationale for repletion of vitamin C following HCT.
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Affiliation(s)
- Mahmood Rasheed
- Department of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Gary Simmons
- Department of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Bernard Fisher
- Department of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Kevin Leslie
- Department of Physics, Virginia Commonwealth University, Richmond, Virginia
| | - Jason Reed
- Department of Physics, Virginia Commonwealth University, Richmond, Virginia
| | - Catherine Roberts
- Department of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Ramesh Natarajan
- Department of Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Alpha Fowler
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia
| | - Amir Toor
- Department of Medicine, Virginia Commonwealth University, Richmond, Virginia
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Aboo Bakkar Z, Fulford J, Gates PE, Jackman SR, Jones AM, Bond B, Bowtell JL. Montmorency cherry supplementation attenuates vascular dysfunction induced by prolonged forearm occlusion in overweight, middle-aged men. J Appl Physiol (1985) 2018; 126:246-254. [PMID: 30496705 DOI: 10.1152/japplphysiol.00804.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Flavonoid supplementation improves brachial artery flow-mediated dilation (FMD), but it is not known whether flavonoids protect against vascular dysfunction induced by ischemia-reperfusion (IR) injury and associated respiratory burst. In a randomized, double-blind, placebo-controlled, crossover study, we investigated whether 4 wk supplementation with freeze-dried Montmorency cherry (MC) attenuated suppression of FMD after IR induced by prolonged forearm occlusion. Twelve physically inactive overweight, middle-aged men (52.8 ± 5.8 yr, BMI: 28.1 ± 5.3 kg/m2) consumed MC (235 mg/day anthocyanins) or placebo capsules for 4 wk, with supplementation blocks separated by 4 wk washout. Before and after each supplementation block, FMD responses and plasma nitrate and nitrite ([ NO2- ]) concentrations were measured at baseline and 15, 30, and 45 min after prolonged (20 min) forearm occlusion. FMD response was significantly depressed by the prolonged occlusion ( P < 0.001). After a 45-min reperfusion, FMD was restored to baseline levels after MC (ΔFMD presupplementation: -30.5 ± 8.4%, postsupplementation: -0.6 ± 9.5%) but not placebo supplementation (ΔFMD presupplementation: -11.6 ± 10.6, postsupplementation: -25.4 ± 4.0%; condition × supplement interaction: P = 0.038). Plasma [ NO2- ] decreased after prolonged occlusion but recovered faster after MC compared with placebo (Δ45 min to baseline; MC: presupplementation: -15.3 ± 9.6, postsupplementation: -6.2 ± 8.1; Placebo: presupplementation: -16.3 ± 5.9, postsupplementation: -27.7 ± 11.1 nmol/l; condition × supplement × time interaction: P = 0.033). Plasma peroxiredoxin concentration ([Prx2]) was significantly higher after MC (presupplementation: 22.8 ± 1.4, postsupplementation: 28.0 ± 2.4 ng/ml, P = 0.029) but not after placebo supplementation (presupplementation: 22.1 ± 2.2, postsupplementation: 23.7 ± 1.5 ng/ml). In conclusion, 4 wk MC supplementation enhanced recovery of endothelium-dependent vasodilatation after IR, in parallel with faster recovery of plasma [ NO2- ], suggesting NO dependency. These protective effects seem to be related to increased plasma [Prx2], presumably conferring protection against the respiratory burst during reperfusion. NEW & NOTEWORTHY This is the first study to demonstrate that 4 wk of Montmorency cherry powder supplementation exerted protective effects on endothelium-dependent vasodilation after transient ischemia-reperfusion injury in overweight, physically inactive, nonmedicated, hypertensive middle-aged men. These effects seem to be due to increased nitric oxide availability, as evidenced by higher plasma nitrite concentration and peak arterial diameter during the flow-mediated dilation measurement. This may be a consequence of increased concentration of peroxiredoxin and other antioxidant systems and, hence, reduced reactive oxygen species exposure.
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Affiliation(s)
| | | | | | - Sarah R Jackman
- Sport and Health Sciences, University of Exeter , United Kingdom
| | - Andrew M Jones
- Sport and Health Sciences, University of Exeter , United Kingdom
| | - Bert Bond
- Sport and Health Sciences, University of Exeter , United Kingdom
| | - Joanna L Bowtell
- Sport and Health Sciences, University of Exeter , United Kingdom
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Aboo Bakkar Z, Fulford J, Gates PE, Jackman SR, Jones AM, Bond B, Bowtell JL. Prolonged forearm ischemia attenuates endothelium-dependent vasodilatation and plasma nitric oxide metabolites in overweight middle-aged men. Eur J Appl Physiol 2018; 118:1565-1572. [PMID: 29785503 PMCID: PMC6060779 DOI: 10.1007/s00421-018-3886-z] [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: 12/29/2017] [Accepted: 05/06/2018] [Indexed: 12/01/2022]
Abstract
Purpose Repeated cycles of endothelial ischemia–reperfusion injury and the resulting respiratory burst contribute to the irreversible pathophysiology of vascular diseases, and yet, the effects of ischemia reperfusion on vascular function, oxidative stress, and nitric oxide (NO) bioavailability have not been assessed simultaneously. Therefore, this study sought to examine the effects of prolonged forearm occlusion and subsequent reperfusion on NO-dependent brachial artery endothelial function. Methods Flow-mediated dilatation was measured at baseline and 15, 30, and 45 min after 20-min forearm occlusion in 14 healthy, but physically inactive middle-aged men (53.7 ± 1.2 years, BMI: 28.1 ± 0.1 kg m−2). Venous blood samples collected from the occluded arm were analyzed for NO metabolites and markers of oxidative stress. Results FMD was significantly depressed after the prolonged occlusion compared to baseline, with a significant reduction 15-min post-occlusion (6.6 ± 0.7 to 2.9 ± 0.4%, p < 0.001); FMD remained depressed after 30 min (4.1 ± 0.6%, p = 0.001), but was not significantly different to baseline after 45-min recovery (5.4 ± 0.7%, p = 0.079). Plasma nitrate (main time effect: p = 0.015) and nitrite (main time effect: p = 0.034) concentrations were significantly reduced after prolonged occlusion. Plasma catalase activity was significantly elevated at 4- (p = 0.016) and 45-min (p = 0.001) post-occlusion, but plasma peroxiredoxin 2 and protein carbonyl content did not change. Conclusions Prolonged forearm occlusion resulted in acute impairment of endothelium-dependent vasodilatation of the brachial artery for at least 30 min after reperfusion. We demonstrate that this vascular dysfunction is associated with oxidative stress and reduced NO bioavailability following reperfusion.
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Affiliation(s)
- Zainie Aboo Bakkar
- Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX1 2LU, UK
| | | | | | - Sarah R Jackman
- Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX1 2LU, UK
| | - Andrew M Jones
- Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX1 2LU, UK
| | - Bert Bond
- Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX1 2LU, UK
| | - Joanna L Bowtell
- Sport and Health Sciences, College of Life and Environmental Sciences, University of Exeter, Exeter, EX1 2LU, UK.
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Weisshaar S, Litschauer B, Kerbel T, Wolzt M. Atorvastatin combined with ticagrelor prevent ischemia-reperfusion induced vascular endothelial dysfunction in healthy young males – A randomized, placebo-controlled, double-blinded study. Int J Cardiol 2018; 255:1-7. [DOI: 10.1016/j.ijcard.2017.12.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 11/28/2017] [Accepted: 12/16/2017] [Indexed: 10/18/2022]
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Weisshaar S, Litschauer B, Eipeldauer M, Hobl EL, Wolzt M. Ticagrelor mitigates ischaemia-reperfusion induced vascular endothelial dysfunction in healthy young males - a randomized, single-blinded study. Br J Clin Pharmacol 2017; 83:2651-2660. [PMID: 28715608 DOI: 10.1111/bcp.13378] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 07/10/2017] [Accepted: 07/12/2017] [Indexed: 01/21/2023] Open
Abstract
AIMS Animal data suggest that ticagrelor but not clopidogrel protects against tissue injury. It is unclear if this effect of ticagrelor is also detectable in humans. We studied the effect of ticagrelor and clopidogrel at standard clinical doses on endothelial dysfunction in an experimental model of forearm vascular ischaemia-reperfusion (IR) injury. METHODS In a randomized, single-blinded trial, 24 subjects underwent forearm blood flow (FBF) measurements in response to the endothelium-dependent vasodilator acetylcholine (ACh) and to glyceryltrinitrate (GTN; endothelium-independent) before and after a 20 min forearm ischaemia. FBF reactivity was assessed after an oral loading dose of ticagrelor or clopidogrel and after 14 days of regular intake of maintenance doses of the study medicines. In addition, the effect on platelet inhibition was evaluated using multiple electrode aggregometry. RESULTS ACh-induced vasodilation was impaired during reperfusion and not completely normalized by acute or chronic treatment with ticagrelor or clopidogrel (post- vs. pre-ischaemia). However, ticagrelor mitigated endothelial dysfunction compared to clopidogrel after loading (FBF AChAUC ratio post- vs. pre-ischaemia: 0.83 [0.70; 0.96] vs. 0.64 [0.56; 0.72]; P = 0.024) and after chronic administration (FBF AChAUC ratio: 0.86 [0.71; 1.00] vs. 0.66 [0.55; 0.77]; P = 0.027). As expected, GTN-induced vasodilation was not affected by ischaemia. Ticagrelor or clopidogrel treatment inhibited platelet activation to a similar degree. CONCLUSION Our data indicate that ticagrelor treatment exerts a greater vascular salutary effect than clopidogrel during reperfusion after an acute vascular occlusion. IR-induced vascular injury cannot be prevented completely by administration of these antiplatelet agents at standard clinical doses.
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Affiliation(s)
- Stefan Weisshaar
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | | | | | - Eva Luise Hobl
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - Michael Wolzt
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
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15
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Protective Role for Antioxidants in Acute Kidney Disease. Nutrients 2017; 9:nu9070718. [PMID: 28686196 PMCID: PMC5537833 DOI: 10.3390/nu9070718] [Citation(s) in RCA: 149] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 06/26/2017] [Accepted: 07/04/2017] [Indexed: 12/16/2022] Open
Abstract
Acute kidney injury causes significant morbidity and mortality in the community and clinic. Various pathologies, including renal and cardiovascular disease, traumatic injury/rhabdomyolysis, sepsis, and nephrotoxicity, that cause acute kidney injury (AKI), induce general or regional decreases in renal blood flow. The ensuing renal hypoxia and ischemia promotes the formation of reactive oxygen species (ROS) such as superoxide radical anions, peroxides, and hydroxyl radicals, that can oxidatively damage biomolecules and membranes, and affect organelle function and induce renal tubule cell injury, inflammation, and vascular dysfunction. Acute kidney injury is associated with increased oxidative damage, and various endogenous and synthetic antioxidants that mitigate source and derived oxidants are beneficial in cell-based and animal studies. However, the benefit of synthetic antioxidant supplementation in human acute kidney injury and renal disease remains to be realized. The endogenous low-molecular weight, non-proteinaceous antioxidant, ascorbate (vitamin C), is a promising therapeutic in human renal injury in critical illness and nephrotoxicity. Ascorbate may exert significant protection by reducing reactive oxygen species and renal oxidative damage via its antioxidant activity, and/or by its non-antioxidant functions in maintaining hydroxylase and monooxygenase enzymes, and endothelium and vascular function. Ascorbate supplementation may be particularly important in renal injury patients with low vitamin C status.
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Vitamin C, Aging and Alzheimer's Disease. Nutrients 2017; 9:nu9070670. [PMID: 28654021 PMCID: PMC5537785 DOI: 10.3390/nu9070670] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/01/2017] [Accepted: 06/13/2017] [Indexed: 02/07/2023] Open
Abstract
Accumulating evidence in mice models of accelerated senescence indicates a rescuing role of ascorbic acid in premature aging. Supplementation of ascorbic acid appeared to halt cell growth, oxidative stress, telomere attrition, disorganization of chromatin, and excessive secretion of inflammatory factors, and extend lifespan. Interestingly, ascorbic acid (AA) was also found to positively modulate inflamm-aging and immunosenescence, two hallmarks of biological aging. Moreover, ascorbic acid has been shown to epigenetically regulate genome integrity and stability, indicating a key role of targeted nutrition in healthy aging. Growing in vivo evidence supports the role of ascorbic acid in ameliorating factors linked to Alzheimer’s disease (AD) pathogenesis, although evidence in humans yielded equivocal results. The neuroprotective role of ascorbic acid not only relies on the general free radical trapping, but also on the suppression of pro-inflammatory genes, mitigating neuroinflammation, on the chelation of iron, copper, and zinc, and on the suppression of amyloid-beta peptide (Aβ) fibrillogenesis. Epidemiological evidence linking diet, one of the most important modifiable lifestyle factors, and risk of Alzheimer's disease is rapidly increasing. Thus, dietary interventions, as a way to epigenetically modulate the human genome, may play a role in the prevention of AD. The present review is aimed at providing an up to date overview of the main biological mechanisms that are associated with ascorbic acid supplementation/bioavailability in the process of aging and Alzheimer’s disease. In addition, we will address new fields of research and future directions.
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Yapp JH, Kamil R, Rozi M, Mohtarrudin N, Loqman MY, Ezamin AR, Ahmad SA, Abu Bakar Z. Trends of reactive hyperaemia responses to repetitive loading on skin tissue of rats - Implications for pressure ulcer prevention. J Tissue Viability 2017; 26:196-201. [PMID: 28438463 DOI: 10.1016/j.jtv.2017.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 03/03/2017] [Accepted: 03/19/2017] [Indexed: 10/19/2022]
Abstract
Tissue recovery is important in preventing tissue deterioration, which is induced by pressure and may lead to pressure ulcers (PU). Reactive hyperaemia (RH) is an indicator used to identify people at risk of PU. In this study, the effect of different recovery times on RH trend is investigated during repetitive loading. Twenty-one male Sprague-Dawley rats (seven per group), with body weight of 385-485 g, were categorised into three groups and subjected to different recovery times with three repetitive loading cycles. The first, second, and third groups were subjected to short (3 min), moderate (10 min), and prolonged (40 min) recovery, respectively, while fixed loading time and pressure (10 min and 50 mmHg, respectively). Peak hyperaemia was measured in the three cycles to determine trends associated with different recovery times. Three RH trends (increasing, decreasing, and inconsistent) were observed. As the recovery time is increased (3 min vs. 10 min vs. 40 min), the number of samples with increasing RH trend decreases (57% vs. 29% vs. 14%) and the number of samples with inconsistent RH trend increases (29% vs. 57% vs. 72%). All groups consists of one sample with decreasing RH trend (14%). Results confirm that different recovery times affect the RH trend during repetitive loading. The RH trend may be used to determine the sufficient recovery time of an individual to avoid PU development.
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Affiliation(s)
- Jong-Heng Yapp
- Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia
| | - Raja Kamil
- Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia.
| | - M Rozi
- Cancer Resource and Education Center, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia
| | - Norhafizah Mohtarrudin
- Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia
| | - M Y Loqman
- Department of Companion Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia
| | - A R Ezamin
- Department of Imaging, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia
| | - Siti Anom Ahmad
- Department of Electrical and Electronic Engineering, Faculty of Engineering, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia
| | - Zuki Abu Bakar
- Department of Veterinary Pre-Clinical Science, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Serdang, Selangor Darul Ehsan, Malaysia
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Davis JL, Paris HL, Beals JW, Binns SE, Giordano GR, Scalzo RL, Schweder MM, Blair E, Bell C. Liposomal-encapsulated Ascorbic Acid: Influence on Vitamin C Bioavailability and Capacity to Protect Against Ischemia-Reperfusion Injury. Nutr Metab Insights 2016; 9:25-30. [PMID: 27375360 PMCID: PMC4915787 DOI: 10.4137/nmi.s39764] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 04/27/2016] [Accepted: 04/29/2016] [Indexed: 12/12/2022] Open
Abstract
Intravenous administration of vitamin C has been shown to decrease oxidative stress and, in some instances, improve physiological function in adult humans. Oral vitamin C administration is typically less effective than intravenous, due in part to inferior vitamin C bioavailability. The purpose of this study was to determine the efficacy of oral delivery of vitamin C encapsulated in liposomes. On 4 separate randomly ordered occasions, 11 men and women were administered an oral placebo, or 4 g of vitamin C via oral, oral liposomal, or intravenous delivery. The data indicate that oral delivery of 4 g of vitamin C encapsulated in liposomes (1) produces circulating concentrations of vitamin C that are greater than unencapsulated oral but less than intravenous administration and (2) provides protection from ischemia–reperfusion-mediated oxidative stress that is similar to the protection provided by unencapsulated oral and intravenous administrations.
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Affiliation(s)
- Janelle L Davis
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Hunter L Paris
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Joseph W Beals
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Scott E Binns
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Gregory R Giordano
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Rebecca L Scalzo
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Melani M Schweder
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
| | - Emek Blair
- Empirical Labs, Fort Collins, Colorado, USA.; Nutritional Biomimetics LLC, Fort Collins, Colorado, USA.; Present address: Valimenta Labs, Fort Collins, Colorado, USA
| | - Christopher Bell
- Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA
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Yang M, Bhopale VM, Thom SR. Ascorbic acid abrogates microparticle generation and vascular injuries associated with high-pressure exposure. J Appl Physiol (1985) 2015; 119:77-82. [PMID: 25977448 DOI: 10.1152/japplphysiol.00183.2015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/12/2015] [Indexed: 11/22/2022] Open
Abstract
We hypothesized that pathological changes associated with elevations in annexin V-positive microparticles (MPs) following high-pressure exposures can be abrogated by ascorbic acid in a murine model. Mice exposed for 2 h to 790-kPa air and killed at 2 or 13 h postdecompression exhibited over threefold elevations in circulating MPs, as well as subgroups bearing Ly6G, CD41, Ter119, CD31, and CD142 surface proteins. There was evidence of significant neutrophil activation, platelet-neutrophil interactions, and vascular injury to brain, omentum, psoas, and skeletal muscles assessed as leakage of high-molecular-weight dextran. Prophylactic ascorbic acid (500 mg/kg ip) administration prevented all postdecompression neutrophil changes and vascular injuries. Ascorbic acid administration immediately after decompression abrogated most changes, but evidence of vascular leakage in the brain and skeletal muscle at 13 h postdecompression persisted. No significant elevations in these parameters occurred after injection of ascorbic acid alone. The findings support the idea that MP production occurring with exposures to elevated gas pressure is an oxidative stress response and that antioxidants may offer protection from pathological effects associated with decompression.
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Affiliation(s)
- Ming Yang
- Department of Emergency Medicine, University of Maryland, Baltimore, Maryland
| | - Veena M Bhopale
- Department of Emergency Medicine, University of Maryland, Baltimore, Maryland
| | - Stephen R Thom
- Department of Emergency Medicine, University of Maryland, Baltimore, Maryland
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The role of prostaglandin and antioxidant availability in recovery from forearm ischemia-reperfusion injury in humans. J Hypertens 2014; 32:339-51. [PMID: 24296519 PMCID: PMC3914903 DOI: 10.1097/hjh.0000000000000033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Endothelial dysfunction, manifesting as attenuated flow-mediated dilation (FMD), is clinically important. Antioxidants may prevent this dysfunction; however, the acute effects of oral administration in humans are unknown. Low flow-mediated constriction (L-FMC), a further parameter of endothelial health, is largely unstudied and the mechanisms for this response unclear. METHODS Twelve healthy participants (five women and seven men) completed three test conditions: control; antioxidant cocktail (α-lipoic acid, vitamins C and E); and prostaglandin inhibitor ingestion (ibuprofen). Ultrasound measurements of brachial artery responses were assessed throughout 5 min of forearm ischemia and 3 min after. Subsequently, an ischemia-reperfusion injury was induced by a 20-min upper arm occlusion. Further, vascular function protocols were completed at 15, 30, and 45 min of recovery. RESULTS Endothelial dysfunction was evident in all conditions. FMD was attenuated at 15 min after ischemia-reperfusion injury (Pre: 6.24 ± 0.58%; Post15: 0.24 ± 0.75%; mean ± SD, P < 0.05), but recovered by 45 min. Antioxidant administration did not preserve FMD compared with control (P > 0.05). The magnitude of L-FMC was augmented at 15 min (Pre: 1.44 ± 0.27%; Post15: 3.75 ± 1.73%; P < 0.05) and recovered by 45 min. Ibuprofen administration produced the largest constrictive response (Pre: -1.13 ± 1.71%; Post15: -5.57 ± 3.82%; time × condition interaction: P < 0.05). CONCLUSION Results demonstrate ischemia-reperfusion injury causes endothelial dysfunction and acute oral antioxidant supplementation fails to reduce its magnitude. Our results also suggest that a lack of shear stress during occlusion combined with suppression of prostaglandin synthesis magnifies L-FMC, possibly due to augmented endothelin-1 expression.
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Oudemans-van Straaten HM, Spoelstra-de Man AM, de Waard MC. Vitamin C revisited. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:460. [PMID: 25185110 PMCID: PMC4423646 DOI: 10.1186/s13054-014-0460-x] [Citation(s) in RCA: 190] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This narrative review summarizes the role of vitamin C in mitigating oxidative injury-induced microcirculatory impairment and associated organ failure in ischemia/reperfusion or sepsis. Preclinical studies show that high-dose vitamin C can prevent or restore microcirculatory flow impairment by inhibiting activation of nicotinamide adenine dinucleotide phosphate-oxidase and inducible nitric oxide synthase, augmenting tetrahydrobiopterin, preventing uncoupling of oxidative phosphorylation, and decreasing the formation of superoxide and peroxynitrite, and by directly scavenging superoxide. Vitamin C can additionally restore vascular responsiveness to vasoconstrictors, preserve endothelial barrier by maintaining cyclic guanylate phosphatase and occludin phosphorylation and preventing apoptosis. Finally, high-dose vitamin C can augment antibacterial defense. These protective effects against overwhelming oxidative stress due to ischemia/reperfusion, sepsis or burn seems to mitigate organ injury and dysfunction, and promote recovery after cardiac revascularization and in critically ill patients, in the latter partially in combination with other antioxidants. Of note, several questions remain to be solved, including optimal dose, timing and combination of vitamin C with other antioxidants. The combination obviously offers a synergistic effect and seems reasonable during sustained critical illness. High-dose vitamin C, however, provides a cheap, strong and multifaceted antioxidant, especially robust for resuscitation of the circulation. Vitamin C given as early as possible after the injurious event, or before if feasible, seems most effective. The latter could be considered at the start of cardiac surgery, organ transplant or major gastrointestinal surgery. Preoperative supplementation should consider the inhibiting effect of vitamin C on ischemic preconditioning. In critically ill patients, future research should focus on the use of short-term high-dose intravenous vitamin C as a resuscitation drug, to intervene as early as possible in the oxidant cascade in order to optimize macrocirculation and microcirculation and limit cellular injury.
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Ashor AW, Lara J, Mathers JC, Siervo M. Effect of vitamin C on endothelial function in health and disease: a systematic review and meta-analysis of randomised controlled trials. Atherosclerosis 2014; 235:9-20. [PMID: 24792921 DOI: 10.1016/j.atherosclerosis.2014.04.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 04/05/2014] [Accepted: 04/05/2014] [Indexed: 12/12/2022]
Abstract
BACKGROUND Observational studies indicate that higher vitamin C intake is associated with reduced risk for cardiovascular diseases. However, randomised controlled trials (RCT) examining the effect of vitamin C on endothelial function (EF) have reported inconsistent results. The aims of this systematic review and meta-analysis were to determine the effect of vitamin C supplementation on EF and to investigate whether the effect was influenced by health status, study duration, dose and route of vitamin C administration. METHODS We searched the Medline, Embase, Cochrane Library, and Scopus databases from inception to May 2013 for studies that met the following criteria: 1) RCT with adult participants, 2) vitamin C administered alone, 3) studies that quantified EF using commonly applied methods including ultrasound, plethysmography and pulse wave analysis. RESULTS Pooling the data from 44 clinical trials showed a significant positive effect of vitamin C on EF (SMD: 0.50, 95% CI: 0.34, 0.66, P < 0.001). Stratification of the analysis by health outcome revealed improved EF in atherosclerotic (SMD: 0.84, 95% CI: 0.41, 1.26, P < 0.001), diabetic (SMD: 0.52, 95% CI: 0.21, 0.82, P < 0.001) and heart failure patients (SMD: 0.48, 95% CI: 0.08, 0.88, P < 0.02) after vitamin C supplementation. The effect size appeared to be unaffected by study design, duration, baseline plasma vitamin C concentration or route of administration of vitamin C. The meta-regression showed a significant positive association between vitamin C dose and improvement in EF (β: 0.00011, 95% CI: 0.00001, 0.00021, P = 0.03). CONCLUSIONS Vitamin C supplementation improved EF. The effect of vitamin C supplementation appeared to be dependent on health status, with stronger effects in those at higher cardiovascular disease risk. PROSPERO Database registration: CRD42013004567, http://www.crd.york.ac.uk/prospero/
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Affiliation(s)
- Ammar W Ashor
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne NE4 5PL, UK; College of Medicine, University of Al-Mustansiriyah, Baghdad, Iraq.
| | - Jose Lara
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne NE4 5PL, UK
| | - John C Mathers
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne NE4 5PL, UK
| | - Mario Siervo
- Human Nutrition Research Centre, Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle on Tyne NE4 5PL, UK
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Aschauer S, Gouya G, Klickovic U, Storka A, Weisshaar S, Vollbracht C, Krick B, Weiss G, Wolzt M. Effect of systemic high dose vitamin C therapy on forearm blood flow reactivity during endotoxemia in healthy human subjects. Vascul Pharmacol 2014; 61:25-9. [PMID: 24512733 DOI: 10.1016/j.vph.2014.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 01/25/2014] [Accepted: 01/30/2014] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Acute inflammation induced by administration of Escherichia coli lipopolysaccharide endotoxin (LPS) reduces plasma concentrations of vitamin C and impairs vascular endothelium-derived nitric oxide (NO) bioactivity. We tested the hypothesis that systemically administered high dose vitamin C restores the endogenous anti-oxidant potential and improves NO-dependent vasodilatation in the forearm vasculature. DESIGN & SETTING 36 male subjects were enrolled in this balanced, placebo controlled cross-over study. Forearm blood flow (FBF) reactivity to acetylcholine (ACh) and glyceryl-trinitrate (GTN), a sensitive test for endothelial function, was assessed at baseline and 4h after LPS-administration (20 IU/kg i.v). The effect of two different doses of intravenous vitamin C (Vitamin C-Injektopas®), 320 mg/kg and 480 mg/kg over 2h, or placebo on forearm vascular function was studied after LPS. MAIN RESULTS LPS caused transient flu-like symptoms, decreased plasma vitamin C concentrations and reduced the ACh-dependent increase in FBF by up to 76%. Vitamin C at a mean plasma concentration of 3.2 or 4.9 mmol/L restored the response to ACh compared to baseline. CONCLUSION High dose systemic vitamin C recovers LPS-induced endothelium-dependent vasodilation in the forearm resistance vasculature. This provides a rationale for a further clinical study of the systemic vitamin C effect under inflammatory conditions.
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Affiliation(s)
- S Aschauer
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - G Gouya
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - U Klickovic
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - A Storka
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - S Weisshaar
- Department of Clinical Pharmacology, Medical University of Vienna, Austria
| | - C Vollbracht
- Pascoe Pharmazeutische Präparate GmbH, Giessen, Germany
| | - B Krick
- Pascoe Pharmazeutische Präparate GmbH, Giessen, Germany
| | - G Weiss
- Pascoe Pharmazeutische Präparate GmbH, Giessen, Germany
| | - M Wolzt
- Department of Clinical Pharmacology, Medical University of Vienna, Austria.
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Sonoda K, Aoi W, Iwata T, Li Y. Anthocyanin-rich Aronia melanocarpa extract improves body temperature maintenance in healthy women with a cold constitution. SPRINGERPLUS 2013; 2:626. [PMID: 24303339 PMCID: PMC3843504 DOI: 10.1186/2193-1801-2-626] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 11/13/2013] [Indexed: 01/17/2023]
Abstract
Purpose Specific anthocyanin-rich dietary factors have been shown to improve metabolic functions associated with thermogenesis in animal studies. Aronia melanocarpa, commonly known as wild chokeberry, contains a high level of anthocyanin that would be expected to maintain body temperature through thermogenesis. We here investigated the effects of Aronia melanocarpa extracts on body temperature and peripheral blood flow in healthy women with a cold constitution. Methods A pre/post comparison trial was performed in 11 women with a cold constitution, who were taking Aronia melanocarpa extracts (150 mg/day) for 4 weeks. Physiological and biochemical parameters, along with psychological tests were examined. Results The subjects’ body surface temperature was significantly higher in the post-trial than in the pre-trial. In psychological tests, factors related to cold were significantly improved by Aronia intake. On the other hand, peripheral blood flow was not affected by Aronia supplementation. Plasma noradrenalin level was significantly elevated by Aronia intake, and subjects with a higher level of 8-hydroxy-2'-deoxyguanosine in the pre-trial showed decreased levels in the post-trial. Conclusions These data suggest that dietary Aronia melanocarpa extract improves the maintenance of body temperature in healthy women with a cold constitution, which may be mediated by noradrenalin and oxidative stress levels.
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Affiliation(s)
- Keisuke Sonoda
- Beijing Gingko Group Co., Ltd, 3F-KeHaiFulin Building, The Chinese Academy of Agricultural Sciences, No.12, Zhongguancun South Avenue, Beijing, Haidian District China
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Weisshaar S, Gouya G, Nguyen D, Kapiotis S, Wolzt M. The LPS-induced increase in circulating microparticles is not affected by vitamin C in humans. Eur J Clin Invest 2013; 43:708-15. [PMID: 23594362 DOI: 10.1111/eci.12096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 03/19/2013] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Microparticles (MP) are considered to promote coagulation. This study aimed to characterize the time course of MP levels and the effect of high-dose vitamin C on MP formation during inflammation in an in vivo Escherichia coli endotoxin (LPS) model. METHODS Microparticle formation was studied in 14 male subjects in a cross-over trial who received either intravenous vitamin C at 320 mg/kg body weight (BW) or 480 mg/kg BW or saline solution in a random order on alternate trial days 3 h after intravenous exposure to LPS (2 ng/kg BW). Venous blood samples were taken before, 3 and 6 h after LPS. D-dimer, leucocyte count, C-reactive protein, plasma vitamin C and body temperature were assessed as inflammatory parameters. MP were detected using flow cytometric analysis and expressed in 10³ MP/mL plasma. RESULTS Microparticles levels were decreased from baseline 848 units [range 431-1705] by 21% to 671 units [253-1586] at 3 h and increased by 32% to 1119 units [288-4443] at 6 h after LPS. This pattern was not influenced by administration of vitamin C, with a change from 730 units [399-1396] at baseline by an increase to 832 units [215-2168] at 3 h to 1055 units [350-4858] at 6 h. MP subpopulations followed similar dynamics. Alterations in inflammatory parameters were independent from vitamin C administration during endotoxemia. CONCLUSION Microparticles are increased in acute systemic inflammation with inconsistent changes in MP subgroups in healthy subjects. Systemic vitamin C administration does not mitigate MP formation and D-dimer levels during acute systemic inflammation, suggesting that MP-induced coagulation activity is not affected by vitamin C.
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Affiliation(s)
- Stefan Weisshaar
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
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Heo JH, Hyon-Lee, Lee KM. The possible role of antioxidant vitamin C in Alzheimer's disease treatment and prevention. Am J Alzheimers Dis Other Demen 2013; 28:120-5. [PMID: 23307795 PMCID: PMC10852723 DOI: 10.1177/1533317512473193] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Oxidative stress is suggested to play a major role in the pathogenesis of Alzheimer's disease (AD). Among the antioxidants, vitamin C has been regarded as the most important one in neural tissue. It also decreases β-amyloid generation and acetylcholinesterase activity and prevents endothelial dysfunction by regulating nitric oxide, a newly discovered factor in the pathogenesis and progression of AD. However, clinical trials using antioxidants, including vitamin C, in patients with AD yielded equivocal results. The current article discusses the relevance of vitamin C in the cellular and molecular pathogenesis of AD and explores its therapeutic potential against this neurodegenerative disorder.
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Affiliation(s)
- Jae-Hyeok Heo
- Department of Neurology, Seoul Medical Center, Seoul, Korea
| | - Hyon-Lee
- Department of Neurology, Seoul National University Hospital, Seoul, Korea
| | - Kyoung-Min Lee
- Department of Neurology, Seoul National University Hospital, Seoul, Korea
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Rakobowchuk M, Parsloe ER, Gibbins SE, Harris E, Birch KM. Prolonged low flow reduces reactive hyperemia and augments low flow mediated constriction in the brachial artery independent of the menstrual cycle. PLoS One 2013; 8:e55385. [PMID: 23393572 PMCID: PMC3564810 DOI: 10.1371/journal.pone.0055385] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 12/29/2012] [Indexed: 12/03/2022] Open
Abstract
Non-invasive forearm ischemia-reperfusion injury and low flow induced vascular dysfunction models provide methods to evaluate vascular function. The role of oestrogen, an endogenous anti-oxidant on recovery from ischemia-reperfusion injury has not been evaluated nor has the impact of prolonged low flow on vascular function been established. Eight healthy women (33±10 yr) attended the lab during the follicular, ovulatory and mid-luteal phases of their menstrual cycles. After 30 minutes of rest, brachial artery vascular function was assessed by ultrasound measurements of diameter changes during 5 minutes of forearm ischemia and 3 minutes after. Subsequently, a 20-minute forearm ischemia period was completed. Further, vascular function assessments were completed 15, 30 and 45 minutes into recovery. Flow-mediated dilation, low-flow-mediated constriction, and reactive hyperaemia proximal to the area of ischemia were determined. Flow-mediated dilation was reduced at 15 minutes of recovery but recovered at 30 and 45 minutes (PRE: 7.1±1.0%, POST15∶4.5±0.6%, POST30∶5. 5±0.7% POST45∶5.9±0.4%, p<0.01). Conversely, low-flow mediated constriction increased (PRE: −1.3±0.4%, POST15: −3.3±0.6%, POST30: −2.5±0.5% POST45: −1.5±0.12%, p<0.01). Reactive hyperaemia was reduced throughout recovery (p<0.05). Data were unaffected by menstrual phase. Prolonged low flow altered vascular function and may relate as much to increased vasoconstriction as with decreased vasodilation. Reductions in anterograde shear and greater retrograde shear likely modulate the brachial artery response, but the reduced total shear also plays an important role. The data suggest substantial alterations in vascular function proximal to areas of ischemia with potential clinical implications following reperfusion.
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Affiliation(s)
- Mark Rakobowchuk
- Department of Biological Sciences, University of Essex, Colchester, United Kingdom.
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Devan AE, Umpierre D, Harrison ML, Lin HF, Tarumi T, Renzi CP, Dhindsa M, Hunter SD, Tanaka H. Endothelial ischemia-reperfusion injury in humans: association with age and habitual exercise. Am J Physiol Heart Circ Physiol 2011; 300:H813-9. [PMID: 21239631 DOI: 10.1152/ajpheart.00845.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Advancing age is a major risk factor for coronary artery disease. Endothelial dysfunction accompanied by increased oxidative stress and inflammation with aging may predispose older arteries to greater ischemia-reperfusion (I/R) injury. Because coronary artery ischemia cannot be induced safely, the effects of age and habitual endurance exercise on endothelial I/R injury have not been determined in humans. Using the brachial artery as a surrogate model of the coronary arteries, endothelial function, assessed by brachial artery flow-mediated dilation (FMD), was measured before and after 20 min of continuous forearm occlusion in young sedentary (n = 10, 24 ± 2 yr) and middle-aged (n = 9, 48 ± 2 yr) sedentary adults to gain insight into the effects of primary aging on endothelial I/R injury. Young (n = 9, 25 ± 1 yr) and middle-aged endurance-trained (n = 9, 50 ± 2 yr) adults were also studied to determine whether habitual exercise provides protection from I/R injury. Fifteen minutes after ischemic injury, FMD decreased significantly by 37% in young sedentary, 35% in young endurance-trained, 68% in middle-aged sedentary, and 50% in middle-aged endurance-trained subjects. FMD returned to baseline levels within 30 min in young sedentary and endurance-trained subjects but remained depressed in middle-aged sedentary and endurance-trained subjects. Circulating markers of antioxidant capacity and inflammation were not related to FMD. In conclusion, advancing age is associated with a greater magnitude and delayed recovery from endothelial I/R injury in humans. Habitual endurance exercise may provide partial protection to the endothelium against this form of I/R injury with advancing age.
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Affiliation(s)
- Allison E Devan
- Cardiovascular Aging Research Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, Texas, USA.
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29
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Maio R, Perticone M, Sciacqua A, Tassone EJ, Naccarato P, Bagnato C, Iannopollo G, Sesti G, Perticone F. Oxidative Stress Impairs Endothelial Function in Nondipper Hypertensive Patients. Cardiovasc Ther 2010; 30:85-92. [DOI: 10.1111/j.1755-5922.2010.00183.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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30
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Loukogeorgakis SP, van den Berg MJ, Sofat R, Nitsch D, Charakida M, Haiyee B, de Groot E, MacAllister RJ, Kuijpers TW, Deanfield JE. Role of NADPH oxidase in endothelial ischemia/reperfusion injury in humans. Circulation 2010; 121:2310-6. [PMID: 20479156 DOI: 10.1161/circulationaha.108.814731] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Reactive oxygen species have been implicated in the pathogenesis of ischemia/reperfusion (IR) injury. Recent studies suggest that NADPH oxidase may be a source of ROS during IR. Using an in vivo model of endothelial IR injury in the arm, we compared the response to IR in healthy volunteers with that in patients with chronic granulomatous disease. These patients have a molecular lesion in a subunit of NADPH oxidase that renders the enzyme inactive. METHODS AND RESULTS Flow-mediated dilatation was used to assess endothelial function in patients with X-linked (NOX2) or autosomal (p47) chronic granulomatous disease. IR injury was induced by 20 minutes of upper limb ischemia followed by reperfusion. Flow-mediated dilatation was determined before IR and after 20 minutes of reperfusion. The response to IR in chronic granulomatous disease patients was compared with that in age- and sex-matched healthy control subjects. Flow-mediated dilatation was expressed as mean and compared statistically with mixed linear models. IR caused a significant reduction in flow-mediated dilatation in control subjects (-5.1%; 95% confidence interval, 6.3 to 3.%; P<0.001; n=11). IR had no effect on endothelial function in NOX2-chronic granulomatous disease patients (-0.9; 95% confidence interval, -2.1 to 0.3; P=0.12; n=11). Similarly, IR-induced reduction in flow-mediated dilatation was not observed in p47-chronic granulomatous disease patients (-1.5%; 95% confidence interval, -3.1 to 0.2; P=0.08; n=6) in contrast to healthy control subjects (-6.5%; 95% confidence interval, -8.2 to -4.9%; P<0.001; n=6). CONCLUSIONS These data indicate, for the first time in humans in vivo, that reactive oxygen species produced by NADPH oxidase are determinants of endothelial function after IR injury in humans. These findings have implications for the design of strategies to limit clinical IR injury.
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van den Boogaard M, Ramakers BP, van Alfen N, van der Werf SP, Fick WF, Hoedemaekers CW, Verbeek MM, Schoonhoven L, van der Hoeven JG, Pickkers P. Endotoxemia-induced inflammation and the effect on the human brain. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:R81. [PMID: 20444270 PMCID: PMC2911704 DOI: 10.1186/cc9001] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 01/26/2010] [Accepted: 05/05/2010] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Effects of systemic inflammation on cerebral function are not clear, as both inflammation-induced encephalopathy as well as stress-hormone mediated alertness have been described. METHODS Experimental endotoxemia (2 ng/kg Escherichia coli lipopolysaccharide [LPS]) was induced in 15 subjects, whereas 10 served as controls. Cytokines (TNF-alpha, IL-6, IL1-RA and IL-10), cortisol, brain specific proteins (BSP), electroencephalography (EEG) and cognitive function tests (CFTs) were determined. RESULTS Following LPS infusion, circulating pro- and anti-inflammatory cytokines, and cortisol increased (P < 0.0001). BSP changes stayed within the normal range, in which neuron specific enolase (NSE) and S100-beta changed significantly. Except in one subject with a mild encephalopathic episode, without cognitive dysfunction, endotoxemia induced no clinically relevant EEG changes. Quantitative EEG analysis showed a higher state of alertness detected by changes in the central region, and peak frequency in the occipital region. Improved CFTs during endotoxemia was found to be due to a practice effect as CFTs improved to the same extent in the reference group. Cortisol significantly correlated with a higher state of alertness detected on the EEG. Increased IL-10 and the decreased NSE both correlated with improvement of working memory and with psychomotor speed capacity. No other significant correlations between cytokines, cortisol, EEG, CFT and BSP were found. CONCLUSIONS Short-term systemic inflammation does not provoke or explain the occurrence of septic encephalopathy, but primarily results in an inflammation-mediated increase in cortisol and alertness. TRIAL REGISTRATION NCT00513110.
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Affiliation(s)
- Mark van den Boogaard
- Department of Intensive Care Medicine, Radboud University Nijmegen Medical Centre, PO Box 9101, Nijmegen 6500HB, the Netherlands.
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Csont T. Nitroglycerin-induced preconditioning: interaction with nitrate tolerance. Am J Physiol Heart Circ Physiol 2010; 298:H308-9. [DOI: 10.1152/ajpheart.01079.2009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Tamás Csont
- Cardiovascular Research Group, Department of Biochemistry, University of Szeged, and Pharmahungary Group, Szeged, Hungary
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Garry A, Edwards DH, Fallis IF, Jenkins RL, Griffith TM. Ascorbic acid and tetrahydrobiopterin potentiate the EDHF phenomenon by generating hydrogen peroxide. Cardiovasc Res 2009; 84:218-26. [PMID: 19592567 PMCID: PMC2761203 DOI: 10.1093/cvr/cvp235] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 07/01/2009] [Accepted: 07/02/2009] [Indexed: 12/11/2022] Open
Abstract
AIMS Our objective was to investigate whether pro-oxidant properties of ascorbic acid (AA) and tetrahydrobiopterin (BH(4)) modulate endothelium-dependent, electrotonically mediated arterial relaxation. METHODS AND RESULTS In studies with rabbit iliac artery (RIA) rings, NO-independent, endothelium-derived hyperpolarizing factor (EDHF)-type relaxations evoked by the sarcoplasmic endoplasmic reticulum Ca(2+)-ATPase inhibitor cyclopiazonic acid and the G protein-coupled agonist acetylcholine (ACh) were enhanced by AA (1 mM) and BH(4) (200 microM), which generated buffer concentrations of H(2)O(2) in the range of 40-80 microM. Exogenous H(2)O(2) potentiated cyclopiazonic acid (CPA)- and ACh-evoked relaxations with a threshold of 10-30 microM, and potentiation by AA and BH(4) was abolished by catalase, which destroyed H(2)O(2) generated by oxidation of these agents in the organ chamber. Adventitial application of H(2)O(2) also enhanced EDHF-type dilator responses evoked by CPA and ACh in RIA segments perfused intraluminally with H(2)O(2)-free buffer, albeit with reduced efficacy. In RIA rings, both control relaxations and their potentiation by H(2)O(2) were overcome by blockade of gap junctions by connexin-mimetic peptides (YDKSFPISHVR and SRPTEK) targeted to the first and second extracellular loops of the dominant vascular connexins expressed in the RIA. Superoxide dismutase attenuated the potentiation of EDHF-type relaxations by BH(4), but not AA, consistent with findings demonstrating a differential role for superoxide anions in the generation of H(2)O(2) by the two agents. CONCLUSION Pro-oxidant effects of AA and BH(4) can enhance the EDHF phenomenon by generating H(2)O(2), which has previously been shown to amplify electrotonic hyperpolarization-mediated relaxation by facilitating Ca(2+) release from endothelial stores.
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Affiliation(s)
- Ambroise Garry
- Department of Diagnostic Radiology, Wales Heart Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - David H. Edwards
- Department of Diagnostic Radiology, Wales Heart Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
| | - Ian F. Fallis
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - Robert L. Jenkins
- School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK
| | - Tudor M. Griffith
- Department of Diagnostic Radiology, Wales Heart Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK
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Frikke-Schmidt H, Lykkesfeldt J. Role of marginal vitamin C deficiency in atherogenesis: in vivo models and clinical studies. Basic Clin Pharmacol Toxicol 2009; 104:419-33. [PMID: 19489786 DOI: 10.1111/j.1742-7843.2009.00420.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Vitamin C is a pivotal redox modulater in many biological reactions of which several remain poorly understood. Naturally, vitamin C has been the subject of many investigations over the past decades in relation to its possible beneficial effects on cardiovascular disease primarily based on its powerful yet general antioxidant properties. However, growing epidemiological, clinical and experimental evidence now suggests a more specific role of ascorbate in vasomotion and in the prevention of atherosclerosis. For example, in contrast to most other biological antioxidants, administration of vitamin C can apparently induce vasodilation. Millions of people worldwide can be diagnosed with vitamin C deficiency according to accepted definitions. In this perspective, the present review examines the evidence for a specific link between vitamin C deficiency and increased risk of atherosclerosis as well as the possible mechanisms by which vitamin C may exert its protective function.
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Affiliation(s)
- Henriette Frikke-Schmidt
- Section of Biomedicine, Department of Disease Biology, Faculty of Life Sciences, University of Copenhagen, Frederiksberg C, Denmark
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Dreger H, Westphal K, Wilck N, Baumann G, Stangl V, Stangl K, Meiners S. Protection of vascular cells from oxidative stress by proteasome inhibition depends on Nrf2. Cardiovasc Res 2009; 85:395-403. [PMID: 19679681 DOI: 10.1093/cvr/cvp279] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
AIMS Increased levels of reactive oxygen species cause oxidative stress and severely damage lipids, proteins, and DNA. We have previously shown that partial proteasome inhibition induces an antioxidative gene pattern in endothelial cells. Here, we elucidate the mechanisms of proteasome inhibitor-mediated upregulation of antioxidative enzymes and cytoprotection. METHODS AND RESULTS Non-toxic proteasome inhibition upregulated mRNA and protein expression of superoxide dismutase 1 (SOD1) and haem oxygenase 1 (HO1) in several human endothelial and vascular smooth muscle cell types. Transcriptional activation of these enzymes was shown by inhibition of RNA polymerase II and nuclear run-on assays. Transfection of endothelial cells with luciferase reporter constructs revealed that upregulation can be largely confined to an antioxidant response element (ARE), which proved to be sufficient for transcriptional activation of SOD1 and HO1. Co-transfection studies and bandshift analyses confirmed binding of the antioxidative transcription factor NF-E2-related factor 2 (Nrf2)-which was stabilized by proteasome inhibition as shown by immunoblots-to the ARE site of HO1. Experiments with aortic endothelial and smooth muscle cells from Nrf2 wild-type and knockout mice revealed an essential role of Nrf2: in wild-type cells, proteasome inhibitor-mediated induction of SOD1 and HO1 was accompanied by protection of vascular cells against oxidative stress as determined by lactate dehydrogenase release assays. In contrast, proteasome inhibitor-mediated induction of antioxidative enzymes and cytoprotection were completely lost in cells from Nrf2 knockout mice. CONCLUSION Nrf2-dependent transcriptional activation of antioxidative enzymes is crucial for proteasome inhibitor-mediated protection of vascular cells against oxidative stress.
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Affiliation(s)
- Henryk Dreger
- Medizinische Klinik für Kardiologie und Angiologie, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
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The effect of oral antioxidants on brachial artery flow-mediated dilation following 5 and 10 min of ischemia. Eur J Appl Physiol 2009; 107:445-53. [PMID: 19669786 DOI: 10.1007/s00421-009-1147-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2009] [Indexed: 12/31/2022]
Abstract
In light of the current methodological developments in flow-mediated dilation (FMD) testing and the recognition that oxidative stress may play an important role in regulating this process, the present study sought to: (1) compare flow-mediated dilation (FMD) following 5 and 10 min of forearm cuff occlusion, and (2) evaluate the role of oxidative stress on vasodilation, both distal and proximal to the cuff. Of the 14 subjects studied, 6 partook solely in a validation study of the antioxidant cocktail (AOC; vitamins C, E, and alpha-lipoic acid), while the remaining 8 subjects underwent FMD assessment in response to 5 and 10 min of forearm occlusion following ingestion of AOC or placebo. Although the efficacy of the AOC was clearly documented by elevated plasma ascorbate levels (approximately 95%) and a reduced free radical concentration (approximately 65%), no effects of acute oral antioxidants were observed. FMD was significantly augmented in response to 10 min of forearm occlusion when compared to 5 min, whether expressed as % change (10.1 +/- 2 vs. 4.5 +/- 1%, respectively) or absolute change in diameter (0.035 +/- 0.005 vs. 0.018 +/- 0.005 cm, respectively). Additionally, post-occlusion shear rate (28,640 +/- 2,799 vs. 18,629 +/- 1,724/s, AUC), FMD/shear rate (approximately 50%), and time to peak dilation (68 +/- 7 vs. 53 +/- 8 s) were greater following 10 min of occlusion. In contrast to previous studies, this investigation has identified a greater brachial artery FMD in response to 10 versus 5 min of forearm ischemia, which appears to be unexplained by oxidative stress.
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Abstract
Vitamins are essential constituents of our diet that have long been known to influence the immune system. Vitamins A and D have received particular attention in recent years as these vitamins have been shown to have an unexpected and crucial effect on the immune response. We present and discuss our current understanding of the essential roles of vitamins in modulating a broad range of immune processes, such as lymphocyte activation and proliferation, T-helper-cell differentiation, tissue-specific lymphocyte homing, the production of specific antibody isotypes and regulation of the immune response. Finally, we discuss the clinical potential of vitamin A and D metabolites for modulating tissue-specific immune responses and for preventing and/or treating inflammation and autoimmunity.
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