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Sharif MA, Bayraktutan U, Arya N, Badger SA, O'Donnell ME, Young IS, Soong CV. Effects of Antioxidants on Endothelial Function in Human Saphenous Vein in an Ex vivo Model. Angiology 2008; 60:448-54. [DOI: 10.1177/0003319708321186] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
This ex vivo study is aimed at determining the beneficial effects of antioxidant agents on human saphenous vein endothelial function. Vein rings harvested during infrainguinal bypass surgery were assessed in an organ bath for endothelium-dependent relaxation, initially without and then with the addition of 10 μM manganese tetrakis benzoic acid porphyrin (MnTBAP), 0.01% N-acetylcysteine (NAC), 0.02% NAC, 10 μM vitamin C, and 100 μM vitamin C. Fifty-five vein rings from 22 patients were analyzed. MnTBAP improved the endothelium-dependent relaxation when compared with control (57.0% vs 37.8%, P < .01). Addition of 0.01% or 0.02% NAC did not improve the endothelium-dependent vasorelaxation (28.2% vs 18.6%, P = ns and 37.8% vs 29.8%, P = ns, respectively). Although 10-μM vitamin C failed to improve endothelial function (50.6% vs 37.2%, P = ns), 100-μM vitamin C significantly enhanced endothelium-dependent relaxation (66.5% vs 38.3%, P < .001). These results suggest that the addition of MnTBAP and high-dose vitamin C can improve the endothelial function of harvested saphenous vein segments in an ex vivo model.
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Affiliation(s)
- Muhammed Anees Sharif
- Department of Vascular and Endovascular Surgery, Belfast City Hospital, Belfast, Northern Ireland
| | - Ulvi Bayraktutan
- Department of Medicine, Queens University of Belfast, Belfast, Northern Ireland
- Division of Stroke Medicine, Nottingham City Hospital, Nottingham, United Kingdom
| | - Nityanand Arya
- Department of Vascular and Endovascular Surgery, Belfast City Hospital, Belfast, Northern Ireland
| | - Stephen A. Badger
- Department of Vascular and Endovascular Surgery, Belfast City Hospital, Belfast, Northern Ireland
| | - Mark E. O'Donnell
- Department of Vascular and Endovascular Surgery, Belfast City Hospital, Belfast, Northern Ireland
| | - Ian S. Young
- Department of Medicine, Queens University of Belfast, Belfast, Northern Ireland
| | - Chee V. Soong
- Department of Vascular and Endovascular Surgery, Belfast City Hospital, Belfast, Northern Ireland
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Lee TF, Tymafichuk CN, Bigam DL, Cheung PY. Effects of postresuscitation N-acetylcysteine on cerebral free radical production and perfusion during reoxygenation of hypoxic newborn piglets. Pediatr Res 2008; 64:256-61. [PMID: 18437097 DOI: 10.1203/pdr.0b013e31817cfcc0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hydrogen peroxide (H2O2) and nitric oxide (NO) contribute to the pathogenesis of cerebral hypoxic-ischemic injury. We evaluated the neuroprotective effect of N-acetyl-l-cysteine (NAC, a free radical scavenger) against oxidative stress and perfusion in a model of neonatal hypoxia-reoxygenation (H-R). Piglets (1-3 d, 1.6-2.3 kg) were randomized into a sham-operated group (without H-R) (n = 5) and two H-R experimental groups (2 h normocapnic alveolar hypoxia followed by 4 h reoxygenation) (n = 7/group). Five minutes after reoxygenation, piglets were given either i.v. saline (H-R controls) or NAC (30 mg/kg bolus then 20 mg/kg/h infusion) in a blinded-randomized fashion. Heart rate, mean arterial pressure, carotid arterial blood flow (transit-time ultrasonic probe), cerebral cortical H2O2 and NO production (electrochemical sensor), cerebral tissue glutathione and nitrotyrosine levels (enzyme-linked immunosorbent assay) were examined. Hypoxic piglets were acidotic (pH 6.88-6.90), which recovered similarly in the H-R groups (p > 0.05 versus shams). Postresuscitation NAC treatment significantly attenuated the increase in cortical H2O2, but not NO, concentration during reoxygenation, with lower cerebral oxidized glutathione levels. NAC-treated piglets had significantly higher carotid oxygen delivery and lower cerebral lactate levels than that of H-R controls with corresponding changes in carotid arterial flow and vascular resistance. In newborn piglets with H-R, postresuscitation administration of NAC reduced cerebral oxidative stress and improved cerebral perfusion.
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Affiliation(s)
- Tze-Fun Lee
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
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Treatment of Patients With Complex Regional Pain Syndrome Type I With Mannitol: A Prospective, Randomized, Placebo-Controlled, Double-Blinded Study. THE JOURNAL OF PAIN 2008; 9:678-86. [DOI: 10.1016/j.jpain.2008.02.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 02/06/2008] [Accepted: 02/12/2008] [Indexed: 11/23/2022]
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Dröge W, Kinscherf R. Aberrant insulin receptor signaling and amino acid homeostasis as a major cause of oxidative stress in aging. Antioxid Redox Signal 2008; 10:661-78. [PMID: 18162053 DOI: 10.1089/ars.2007.1953] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The mechanisms leading to the increase in free radical-derived oxidative stress in "normal aging" remains obscure. Here we present our perspective on studies from different fields that reveal a previously unnoticed vicious cycle of oxidative stress. The plasma cysteine concentrations during starvation in the night and early morning hours (the postabsorptive state) decreases with age. This decrease is associated with a decrease in tissue concentrations of the cysteine derivative and quantitatively important antioxidant glutathione. The decrease in cysteine reflects changes in the autophagic protein catabolism that normally ensures free amino acid homeostasis during starvation. Autophagy is negatively regulated by the insulin receptor signaling cascade that is enhanced by oxidative stress in the absence of insulin. This synopsis of seemingly unrelated processes reveals a novel mechanism of progressive oxidative stress in which decreasing antioxidant concentrations and increasing basal (postabsorptive) insulin receptor signaling activity compromise not only the autophagic protein catabolism but also the activity of FOXO transcription factors (i.e., two functions that were found to have an impact on lifespan in several animal models of aging). In addition, the aging-related decrease in glutathione levels is likely to facilitate certain "secondary" disease-related mechanisms of oxidative stress. Studies on cysteine supplementation show therapeutic promise.
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Affiliation(s)
- Wulf Dröge
- Department of Research and Development, Immunotec Inc, Vaudreuil, Québec, Canada.
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Nagarajan V, Kulkarni N, Contractor N. Intra-arterial N-acetylcysteine. Clin Toxicol (Phila) 2008; 46:915. [DOI: 10.1080/15563650701790981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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56
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Elmes MJ, McMullen S, Gardner DS, Langley-Evans SC. Prenatal diet determines susceptibility to cardiac ischaemia–reperfusion injury following treatment with diethylmaleic acid and N-acetylcysteine. Life Sci 2008; 82:149-55. [DOI: 10.1016/j.lfs.2007.10.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 10/25/2007] [Accepted: 10/25/2007] [Indexed: 11/30/2022]
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Sahin G, Yalcin AU, Akcar N. Effect of N-Acetylcysteine on Endothelial Dysfunction in Dialysis Patients. Blood Purif 2007; 25:309-15. [PMID: 17643057 DOI: 10.1159/000106103] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Accepted: 05/18/2007] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Patients with K/DOQI stage 5 chronic kidney disease (CKD) have higher incidence of cardiovascular events due to the oxidative stress and endothelial dysfunction (ED). The aim of this study is to evaluate the effects of N-acetylcysteine (NAC), which might prevent cardiovascular events by improving oxidative stress on endothelial cells in patients with CKD. METHODS Thirty uremic patients (age 40 +/- 12 years, 6 males) on hemodialysis (HD) were evaluated for ED by using high-resolution Doppler ultrasound of brachial artery before and after 6 weeks of oral NAC (2 x 600 mg) medication. Also, 13 healthy controls (35 +/- 9 years, 5 males) were included in the study. Reactive hyperemia following 5 min forearm ischemia was accepted as endothelium-dependent vasodilatation (flow-mediated dilatation; FMD) and compared to endothelium-independent vasodilatation in response to sublingual glyceril trinitrate (GTN). RESULTS Patients on HD had lower DeltaFMD (0.28 +/- 0.17 vs. 0.41 +/- 0.11, p < 0.05) and FMD% (7.5 +/- 5.05 vs. 11.33 +/- 2.95, p < 0.05) than the controls. Baseline DeltaGTN and GTN% were similar in two groups. NAC treatment significantly increased the DeltaFMD (0.41 +/- 0.11, p < 0.001 vs. baseline) and FMD% (10.59 +/- 3.22, p < 0.01 vs. baseline) of patients on HD, while it had no effect on DeltaGTN and GTN%. CONCLUSION These results suggest that NAC treatment could improve the ED by preventing the reduction of FMD in patients on HD.
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Affiliation(s)
- Garip Sahin
- Department of Nephrology, Osmangazi University Medical School, Eskisehir, Turkey.
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Giustarini D, Dalle-Donne I, Lorenzini S, Milzani A, Rossi R. Age-related influence on thiol, disulfide, and protein-mixed disulfide levels in human plasma. J Gerontol A Biol Sci Med Sci 2006; 61:1030-8. [PMID: 17077195 DOI: 10.1093/gerona/61.10.1030] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this study, plasma levels of both low-molecular-mass sulfhydryls/disulfides and mixed disulfides with proteins in 41 healthy humans aged 21-92 years were measured, with the aim of assessing whether there is a shift of the thiol/disulfide balance during aging and verifying some of the possible effects of the thiol imbalance. Our data suggest that aging is strictly correlated to a decrease in plasma glutathione and cysteinylglycine with the concomitant increase of most oxidized forms of thiols and a parallel increase in total cysteine and total homocysteine, probably due to an augmented efflux of these amino acids from various organs. The occurrence of two distinct regulatory systems for plasmatic pools of glutathione/cysteinylglycine on the one hand and cysteine/homocysteine on the other hand is hypothesized.
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Affiliation(s)
- Daniela Giustarini
- Department of Neuroscience, Pharmacology Unit, University of Siena, via A. Moro 4, I-53100, Siena, Italy.
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Koramaz I, Pulathan Z, Usta S, Karahan SC, Alver A, Yaris E, Kalyoncu NI, Ozcan F. Cardioprotective effect of cold-blood cardioplegia enriched with N-acetylcysteine during coronary artery bypass grafting. Ann Thorac Surg 2006; 81:613-8. [PMID: 16427861 DOI: 10.1016/j.athoracsur.2005.08.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Revised: 07/29/2005] [Accepted: 08/15/2005] [Indexed: 11/24/2022]
Abstract
BACKGROUND Cold-blood cardioplegia is a well-known method in coronary artery bypass graft surgery, and several authors have used various agents in the enrichment of cold-blood cardioplegia to decrease ischemia-reperfusion injury seen during surgery. N-acetylcysteine, which can increase glutathione levels, is one of the agents added to cardioplegic solutions to decrease myocardial injury. This study was planned to assess the efficiency of N-acetylcysteine-enriched cold-blood cardioplegia on early reperfusion injury in patients with ischemic heart disease undergoing coronary artery bypass grafting, using measurements of cardiac troponin I and malondialdehyde release. METHODS Thirty patients (11 women and 19 men) with left ventricular ejection fraction greater than 0.40 scheduled for coronary artery bypass grafting were randomly divided into two groups. We used cold-blood cardioplegia enriched with N-acetylcysteine (50 mg per kilogram of body weight) in the first group and cold-blood cardioplegia alone in the second group. Hemodynamic variables and clinical properties of the patients were preoperatively and postoperatively evaluated. Enzyme releases were measured in the early hours after the operation. RESULTS In the N-acetylcysteine-enriched group cardiac troponin I levels were lower than in the N-acetylcysteine-free group, and this difference was statistically significant. Cardiac troponin I levels increased in both groups in the 6th and 12th hours postoperatively, but there was a statistically significant difference between the two groups. Malondialdehyde levels were significantly higher in the N-acetylcysteine-free group after the 6th, 12th, 24th, and 48th hours postoperatively when compared with the N-acetylcysteine-enriched group. CONCLUSIONS N-acetylcysteine-supplemented cold-blood cardioplegia minimizes myocardial injury in the early hours after and during the cardiac surgery.
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Affiliation(s)
- Ismail Koramaz
- Department of Cardiovascular Surgery, School of Medicine, Karadeniz Technical University, Trabzon, Turkey.
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Yenicerioglu Y, Yilmaz O, Sarioglu S, Ormen M, Akan P, Celik A, Camsari T. Effects of N-acetylcysteine on radiocontrast nephropathy in rats. ACTA ACUST UNITED AC 2006; 40:63-9. [PMID: 16452059 DOI: 10.1080/00365590500329445] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE N-acetylcysteine (NAC) has yielded some promising results recently in the prevention of radiocontrast nephropathy (RCN). In this study, the structural and functional effects of NAC on RCN were analyzed. MATERIAL AND METHODS Twenty-eight Wistar rats were randomized into four groups, as follows: Group 1, controls; Group 2, contrast; Group 3, contrast+NAC; and Group 4, NAC. All rats were deprived of water for 24 h and then contrast medium (ioxoglate; 10 ml/kg) was administered to Groups 2 and 3. NAC (50 mg/kg) was introduced enterally to Groups 3 and 4 at a dose of 50 mg/kg in 0.5 ml of distilled water, in four sequential doses 12h apart, starting after 12?h of water deprivation. After 4 days, rats were sacrificed. Creatinine clearance was calculated. The malondialdehyde (MDA) level was quantified in tissue samples. Slides stained with hematoxylin-eosin and periodic acid-Schiff were examined by means of light microscopy. Each tubular cross-section from all images was scored as either mild (preserved brush border, no necrosis), moderate (loss of brush border, no necrosis) or severe (loss of brush border accompanied by necrosis) and the frequencies of these lesion severities were compared. RESULTS Mean baseline serum creatinine levels and creatinine clearances were similar in all groups. Mean serum creatinine level increased significantly only in Group 2 (0.6+/-0.1 vs 0.7+/-0.2 mg/dl; p<0.05). Tissue MDA levels were similar in all groups. Moderate (13.8%+/-1.5% vs 42%+/-1.4%; p<0.05) and severe (0% vs 40%+/-2.1%; p<0.05) lesions were significantly more frequent in Group 2 compared to Group 1. The frequency of severe lesions in Group 3 was found to be halved compared to that in Group 1 (40%+/-2.1% vs 20.2%+/-0.86%; p<0.05). CONCLUSION NAC protects the kidneys following exposure to contrast medium as it decreased the severity of tubular lesions in rats.
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Elesber AA, Bonetti PO, Lerman A. Endothelial function and cerebrovascular disease: Implications for diagnosis and treatment. CURRENT TREATMENT OPTIONS IN CARDIOVASCULAR MEDICINE 2006; 8:213-9. [PMID: 16635440 DOI: 10.1007/s11936-006-0014-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cerebrovascular disease remains one of the most common causes of morbidity and mortality in the United States. There is strong evidence to implicate endothelial dysfunction in the initiation and progression of atherosclerosis and its complications. It is now well known that endothelial dysfunction represents a systemic syndrome involving multiple vascular beds, including the cerebral vasculature. Currently, no gold standard treatment for endothelial dysfunction exists. Nonetheless, several treatment strategies have been found to be helpful in improving endothelial function. A few of these strategies have been implicated in stroke risk reduction as well, adding another line of evidence to the relationship between endothelial function and cerebrovascular disease.
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Affiliation(s)
- Ahmad A Elesber
- Division of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA
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N-acetylcysteine ameliorates amphotericin-induced nephropathy in rats. Nephron Clin Pract 2006; 99:p23-7. [PMID: 15637469 DOI: 10.1159/000081799] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Accepted: 08/24/2004] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Amphotericin B may cause acute reduction in renal function. N-acetylcysteine (NAC) has a renoprotective activity in several nephrotoxic renal insults, but its effect on amphotericin-induced renal failure has not been investigated yet. METHODS Acute renal failure was induced in 30 Sprague-Dawley rats by a single intraperitoneal injection of amphotericin B (50 mg/kg). NAC (10 mg/kg) in isotonic saline or isotonic saline alone were administered daily for 4 days, starting 1 day before the amphotericin B injection. Glomerular filtration rate (GFR) was assessed using 99m-technetium diethylene triaminepentaacetic acid. Before and following amphotericin B administration, a 24-hour urine collection was performed for sodium, potassium and magnesium determination. The kidneys were preserved for pathologic examination. RESULTS Amphotericin B induced a significant decrease of GFR in both groups. Four days after amphotericin injection the GFR in the NAC-treated group was significantly higher than in the control group (0.62 +/- 0.20 vs. 0.46 +/- 0.14 ml/min, p = 0.042). Histologic signs of acute tubular necrosis were attenuated in the NAC-treated group. There were no significant differences between the groups in sodium, potassium and magnesium urine excretion after amphotericin injection. CONCLUSIONS NAC treatment exerted a renoprotective effect on deterioration of GFR in a rat model of amphotericin-induced renal failure. No functional protection on tubular function, as obviated by similar polyuria and urine losses of potassium and magnesium in both groups, was observed.
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Niemi TT, Munsterhjelm E, Pöyhiä R, Hynninen MS, Salmenperä MT. The effect of N-acetylcysteine on blood coagulation and platelet function in patients undergoing open repair of abdominal aortic aneurysm. Blood Coagul Fibrinolysis 2006; 17:29-34. [PMID: 16607076 DOI: 10.1097/01.mbc.0000195922.26950.89] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
N-acetylcysteine (NAC) may offer renal and hepatic protection during surgery, but in experimental studies it has been shown to impair coagulation. Since very little is known about the effects of NAC on blood coagulation in surgical patients, we studied its effects during abdominal aortic reconstruction. NAC (a bolus of 150 mg/kg followed by a continuous 24-h infusion of 150 mg/kg) or the same volume of placebo was given intravenously, in a randomized double-blinded fashion, to 20 patients undergoing abdominal aortic aneurysm repair. The haematocrit, platelet count, prothrombin time, thromboelastometry, and platelet aggregation were studied during and after surgery. Total blood loss was also measured. The median (25th-75th percentiles) decrease of the prothrombin time value was 33.0% (30-37%) after NAC treatment and 6.5% (4-8%) after placebo (P<0.001). Postoperative prothrombin time values remained lower in the patients receiving NAC. In thromboelastometry tracings the coagulation time was more prolonged after the bolus of NAC (P=0.02). Platelet aggregation induced with adenosine diphosphate decreased after NAC but not after placebo. Low prothrombin time values before and after bolus infusions were associated with increased blood loss (P=0.008 and P=0.015, respectively). NAC has anticoagulant and platelet-inhibiting properties in patients undergoing major vascular surgery. This abnormal haemostatic activity should be considered when NAC is administered to patients with increased bleeding risk.
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Affiliation(s)
- Tomi T Niemi
- Department of Anaesthesiology and Intensive Care Medicine, Helsinki University Central Hospital, Finland.
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64
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Oxidant stress—a major cause of reduced endothelial nitric oxide availability in cardiovascular disease. Eur J Clin Pharmacol 2005. [DOI: 10.1007/s00228-005-0012-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Forman JP, Stampfer MJ, Curhan GC. Non-narcotic analgesic dose and risk of incident hypertension in US women. Hypertension 2005; 46:500-7. [PMID: 16103274 DOI: 10.1161/01.hyp.0000177437.07240.70] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Acetaminophen, ibuprofen, and aspirin are the most commonly used drugs in the United States. Although the frequency of their use has been associated with hypertension, prospective data examining the dose of these drugs and risk of hypertension are lacking. Furthermore, whether certain indications for analgesic use, particularly headache, mediate the association is unclear. We conducted 2 prospective cohort studies among older women 51 to 77 years of age (n=1903) from the Nurses' Health Study I and younger women 34 to 53 years of age (n=3220) from the Nurses' Health Study II who completed detailed supplemental questionnaires pertaining to their analgesic use and who did not have hypertension at baseline. We analyzed incident hypertension according to categories of average daily dose of acetaminophen, nonsteroidal anti-inflammatory drugs, and aspirin. Information on indications for analgesic use as well as relevant confounders was also gathered prospectively. Compared with women who did not use acetaminophen, the multivariable adjusted relative risk for those who took >500 mg per day was 1.93 (1.30 to 2.88) among older women and 1.99 (1.39 to 2.85) among younger women. For nonsteroidal anti-inflammatory drugs, similar comparisons yielded multivariable relative risks of 1.78 (1.21 to 2.61) among older women and 1.60 (1.10 to 2.32) among younger women. These associations remained significant among women who did not report headache. Aspirin dose was not significantly associated with hypertension. Higher daily doses of acetaminophen and nonsteroidal anti-inflammatory drugs independently increase the risk of hypertension in women. Because acetaminophen and nonsteroidal anti-inflammatory drugs are commonly used, they may contribute to the high prevalence of hypertension in the United States.
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Affiliation(s)
- John P Forman
- Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.
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Asselbergs FW, van der Harst P, Jessurun GAJ, Tio RA, van Gilst WH. Clinical impact of vasomotor function assessment and the role of ACE-inhibitors and statins. Vascul Pharmacol 2005; 42:125-40. [PMID: 15792930 DOI: 10.1016/j.vph.2005.01.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Impaired endothelial function is recognised as one of the earliest events of atherogenesis. Endothelium-dependent vasomotion has been the principal method to assess endothelial function. In this article, we will discuss the clinical value of the different techniques to evaluate endothelium-dependent vasomotion. To date, there seems not to be a simple and reliably endothelial function test to identify asymptomatic subjects at increased risk for cardiovascular disease in clinical practice. Recent studies indicate that pharmacological interventions, in particular with ACE-inhibitors and statins, might improve endothelial function. However, there is no solid evidence that improvement of endothelial function is a necessity for the observed reduction in cardiovascular events by these compounds. Overall, at this moment, there is no place in clinical practice for the use of endothelial function as a method for risk assessment or target of pharmacological interventions.
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Affiliation(s)
- Folkert W Asselbergs
- Department of Clinical Pharmacology, University of Groningen, Groningen, The Netherlands.
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67
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Dröge W. Oxidative enhancement of insulin receptor signaling: experimental findings and clinical implications. Antioxid Redox Signal 2005; 7:1071-7. [PMID: 15998262 DOI: 10.1089/ars.2005.7.1071] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Signaling through the insulin receptor and several other receptor tyrosine kinases is subject to redox regulation. Prolonged exposure to hydrogen peroxide impairs the action of insulin, and may account to some extent for the decreased insulin responsiveness in hyperglycemic diabetic patients. However, insulin receptor kinase (IRK) autophosphorylation and/or kinase activity were found to be markedly enhanced by a more limited exposure to hydrogen peroxide or by an oxidative shift in the thiol/disulfide redox status. Oxidative enhancement of IRK function may be mediated by two different mechanisms with similar effects, i.e., by direct oxidative activation of IRK activity or by oxidative inactivation of a protein tyrosine phosphatase, which otherwise down-regulates IRK-mediated signaling. As both mechanisms enhance IRK activity in the absence of insulin, there is a strong possibility that the background IRK activity in the postabsorptive period may be abnormally increased in certain oxidative conditions and thereby disturb the metabolism of glucose and other energy substrates. This remains to be tested. In line with the oxidative enhancement of IRK activity, clinical studies have shown that treatment with a thiol-containing antioxidant increases the postabsorptive glucose and/or insulin concentrations (i.e., the HOMA-R index) at least under certain conditions. This effect may have therapeutic implications.
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Affiliation(s)
- Wulf Dröge
- Tumor Immunology Program, Deutsches Krebsforschungszentrum, Heidelberg, Germany.
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Misra D, Leibowitz K, Gowda RM, Shapiro M, Khan IA. Role of N-acetylcysteine in prevention of contrast-induced nephropathy after cardiovascular procedures: a meta-analysis. Clin Cardiol 2005; 27:607-10. [PMID: 15562929 PMCID: PMC6654550 DOI: 10.1002/clc.4960271106] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Contrast-induced nephropathy is one of the common causes of acute renal insufficiency after cardiovascular procedures. HYPOTHESIS The objective of this paper was to analyze the published data on the usefulness of N-acetylcysteine in the prevention of contrast-induced nephropathy after these procedures. METHODS Trials were selected if they were prospective, randomized, controlled, had selected patients with impaired renal function, used low-osmolality, nonionic contrast media intra-arterially, administered a total of four doses of N-acetylcysteine in addition to intravenous saline hydration, and had contrast-induced nephropathy as their primary outcome. Contrast-induced nephropathy was defined as an increase in serum creatinine concentration by >0.5 mg/dl or a 25% increase above baseline at or within 48 h post procedure. Meta-analysis was performed using the Fisher's Combined Test with a measure of effect size. The magnitude of the N-acetylcysteine effect was estimated using random-effects models. Homogeneity was evaluated using the chi-square test of homogeneity and standard Q statistic. Reporting bias was explored by the Rosenthal method. RESULTS The Fisher's Combined Test was significant at p < 0.005 in favor of N-acetylcysteine. The size of the N-acetylcysteine effect was to reduce contrast-induced nephropathy by 20%. There was a 62% relative risk reduction in contrast-induced nephropathy with N-acetylcysteine using a fixed-effects model, and a 70% relative risk reduction using the random-effects model. In addition, we found that 27 unpublished trials showing no effects of N-acetylcysteine would exist to overturn the combined significance of p < 0.005 of the five trials in our meta-analysis. CONCLUSION Oral administration of N-acetylcysteine in addition to intravenous saline hydration has a beneficial effect in the prevention of contrast-induced nephropathy after cardiovascular procedures in patients with impaired renal function.
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Affiliation(s)
- Deepika Misra
- Division of Cardiology, Beth Israel Medical Center, New York, New York
| | - Keith Leibowitz
- Division of Cardiology, Beth Israel Medical Center, New York, New York
| | - Ramesh M. Gowda
- Division of Cardiology, Beth Israel Medical Center, New York, New York
| | - Michael Shapiro
- Division of Cardiology, Beth Israel Medical Center, New York, New York
| | - Ijaz A. Khan
- Division of Cardiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Vita JA. Polyphenols and cardiovascular disease: effects on endothelial and platelet function. Am J Clin Nutr 2005; 81:292S-297S. [PMID: 15640493 DOI: 10.1093/ajcn/81.1.292s] [Citation(s) in RCA: 331] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Epidemiologic studies suggest that higher polyphenol intake from fruits and vegetables is associated with decreased risk for cardiovascular disease. The mechanisms explaining this observation remain unclear. This review summarizes data suggesting that flavonoids improve endothelial function and inhibit platelet aggregation in humans. The vascular endothelium is a critical regulator of vascular homeostasis, and endothelial dysfunction contributes to the pathogenesis and clinical expression of coronary artery disease. Platelet aggregation is a central mechanism in the pathogenesis of acute coronary syndromes, including myocardial infarction and unstable angina. For these reasons, the observed effects of flavonoids on endothelial and platelet function might explain, in part, the observed beneficial effects of flavonoids on cardiovascular disease risk.
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Affiliation(s)
- Joseph A Vita
- Evans Department of Medicine and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, USA.
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70
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Webb JG, Pate GE, Humphries KH, Buller CE, Shalansky S, Al Shamari A, Sutander A, Williams T, Fox RS, Levin A. A randomized controlled trial of intravenous N-acetylcysteine for the prevention of contrast-induced nephropathy after cardiac catheterization: lack of effect. Am Heart J 2004; 148:422-9. [PMID: 15389228 DOI: 10.1016/j.ahj.2004.03.041] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Contrast-induced nephropathy (CIN) after cardiac catheterization is common in patients with preexisting renal dysfunction. Studies of oral acetylcysteine to prevent CIN have produced conflicting results. Intravenous N-acetylcysteine (NAC) has logistic advantages in this setting. The objective of this study was to evaluate, in a blinded, randomized, placebo-controlled fashion, whether intravenous NAC reduced CIN in the setting of cardiac catheterization in patients with preexisting renal insufficiency. METHODS Patients with renal dysfunction undergoing cardiac catheterization were randomly assigned to intravenous NAC 500 mg immediately before the procedure or placebo. All patients received isotonic saline (200 mL) beforehand, followed by 1.5 mL/kg per hour for 6 hours, unless contraindicated. Exclusion criteria included acute renal failure, creatinine >400 micromol/L, concurrent dialysis, unstable clinical status, and prior NAC use. Baseline creatinine was obtained immediately before the procedure and repeated 2 to 8 days later. The primary end point was the occurrence of CIN defined as a reduction in creatinine clearance from baseline of >5 mL/min (Cockcroft-Gault formula). RESULTS The study was terminated early because of a determination of futility by the Data Safety Monitoring Committee after enrollment of 487 patients. The median baseline creatinine clearance was 44 mL/min (interquartile range, 33, 55). Median contrast received was 120 mL (interquartile range, 80, 175). Baseline characteristics were similar in the two groups. Altogether, 98 (22.0%) subjects had the primary end point: 23.3% in the NAC group and 20.7% in the placebo arm (P =.57). CONCLUSIONS In this large, randomized trial, enrolling a high-risk group of patients with impaired renal function, intravenous NAC was ineffective in preventing CIN.
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Affiliation(s)
- John G Webb
- Division of Cardiology, Pharmacy Department, St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
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71
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Rodrigues AJ, Evora PRB, Schaff HV. Protective effect of N-acetylcysteine against oxygen radical-mediated coronary artery injury. Braz J Med Biol Res 2004; 37:1215-24. [PMID: 15273823 DOI: 10.1590/s0100-879x2004000800012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The present study investigated the protective effect of N-acetylcysteine (NAC) against oxygen radical-mediated coronary artery injury. Vascular contraction and relaxation were determined in canine coronary arteries immersed in Kreb's solution (95% O2-5% CO2), incubated or not with NAC (10 mM), and exposed to free radicals (FR) generated by xanthine oxidase (100 mU/ml) plus xanthine (0.1 mM). Rings not exposed to FR or NAC were used as controls. The arteries were contracted with 2.5 microM prostaglandin F2alpha. Subsequently, concentration-response curves for acetylcholine, calcium ionophore and sodium fluoride were obtained in the presence of 20 microM indomethacin. Concentration-response curves for bradykinin, calcium ionophore, sodium nitroprusside, and pinacidil were obtained in the presence of indomethacin plus Nomega-nitro-L-arginine (0.2 mM). The oxidative stress reduced the vascular contraction of arteries not exposed to NAC (3.93 +/- 3.42 g), compared to control (8.56 +/- 3.16 g) and to NAC group (9.07 +/- 4.0 g). Additionally, in arteries not exposed to NAC the endothelium-dependent nitric oxide (NO)-dependent relaxation promoted by acetylcholine (1 nM to 10 microM) was also reduced (maximal relaxation of 52.1 +/- 43.2%), compared to control (100%) and NAC group (97.0 +/- 4.3%), as well as the NO/cyclooxygenase-independent receptor-dependent relaxation provoked by bradykinin (1 nM to 10 microM; maximal relaxation of 20.0 +/- 21.2%), compared to control (100%) and NAC group (70.8 +/- 20.0%). The endothelium-independent relaxation elicited by sodium nitroprusside (1 nM to 1 microM) and pinacidil (1 nM to 10 microM) was not affected. In conclusion, the vascular dysfunction caused by the oxidative stress, expressed as reduction of the endothelium-dependent relaxation and of the vascular smooth muscle contraction, was prevented by NAC.
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Affiliation(s)
- A J Rodrigues
- Divisão de Cirurgia Torácica e Cardiovascular, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
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72
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Briguori C, Colombo A, Airoldi F, Violante A, Castelli A, Balestrieri P, Paolo Elia P, Golia B, Lepore S, Riviezzo G, Scarpato P, Librera M, Focaccio A, Ricciardelli B. N-acetylcysteine versus fenoldopam mesylate to prevent contrast agent-associated nephrotoxicity. J Am Coll Cardiol 2004; 44:762-5. [PMID: 15312855 DOI: 10.1016/j.jacc.2004.04.052] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2004] [Revised: 04/14/2004] [Accepted: 04/19/2004] [Indexed: 11/21/2022]
Abstract
OBJECTIVES We performed a study to assess the efficacy of fenoldopam mesylate (a specific agonist of the dopamine-1 receptor) as compared with N-acetylcysteine (NAC) in preventing contrast agent-associated nephrotoxicity (CAN). BACKGROUND Prophylactic administration of NAC, along with hydration, prevents CAN in patients with chronic renal insufficiency who are undergoing contrast media administration. Preliminary data support the hypothesis that fenoldopam might be as effective as NAC. METHODS One hundred ninety-two consecutive patients with chronic renal insufficiency, referred to our institution for coronary and/or peripheral procedures, were assigned randomly to receive 0.45% saline intravenously and NAC (1,200 mg orally twice daily; NAC group; n = 97) or fenoldopam (0.10 microg/kg/min; fenoldopam group; n = 95) before and after a nonionic, iso-osmolality contrast dye administration. RESULTS Baseline creatinine levels were similar in the two groups: NAC group = 1.72 mg/dl (interquartile range, 1.55 to 1.90 mg/dl) and fenoldopam group = 1.75 mg/dl (interquartile range, 1.62 to 2.01 mg/dl) (p = 0.17). An increase of at least 0.5 mg/dl of the creatinine concentration 48 h after the procedure occurred in 4 of 97 patients (4.1%) in the NAC group and in 13 of 95 patients (13.7%) in the fenoldopam group (p = 0.019; odds ratio 0.27; 95% confidence interval 0.08 to 0.85). The amount of contrast media administration was similar in the two groups (NAC group = 160 +/- 82 ml; fenoldopam group = 168 +/- 104 ml; p = 0.54). CONCLUSIONS N-acetylcysteine seems to be more effective than fenoldopam in preventing CAN.
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Affiliation(s)
- Carlo Briguori
- Laboratory of Interventional Cardiology and Department of Cardiology, Clinica Mediterranea, Naples, Italy.
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Jeremias A, Dusa C, Forudi F, Jacobsen DW, Vince DG, Nissen SE, Tuzcu EM. N-acetyl-cysteine in the prevention of vascular restenosis after percutaneous balloon angioplasty. Int J Cardiol 2004; 95:255-60. [PMID: 15193829 DOI: 10.1016/j.ijcard.2003.05.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2003] [Revised: 05/26/2003] [Accepted: 05/29/2003] [Indexed: 10/26/2022]
Abstract
BACKGROUND Vascular inflammation generating oxidized metabolites at the site of balloon angioplasty is believed to play a major role in the process of vessel restenosis. Glutathione, the most potent endogenous antioxidant, may have protective effects after angioplasty by suppressing local inflammatory response. The aim of the study was to test the hypothesis that oral administration of N-acetyl-cysteine (NAC, a precursor of glutathione) reduces restenosis in an animal model of vascular injury. METHODS In New Zealand white rabbits, an atherosclerotic lesion was introduced to both iliac arteries by air denudation of the endothelium while feeding the animals a high-cholesterol diet. After 4 weeks, all animals underwent balloon angioplasty of the endothelial injury site and half of the group was started on 150 mg/kg NAC per day. Quantitative angiography was performed prior to the angioplasty and at the final procedure 3 weeks later. Glutathione levels were determined in all animals at the beginning and the end of the study. RESULTS Although not statistically significant, plasma glutathione level increased in the NAC group from 32.4+/-4.4 to 39.7+/-11.6 micromol/l, while it decreased from 30.6+/-13.4 to 28.3+/-11.5 micromol/l in the control group. During the study period, 6 vessels occluded leaving 14 vessels for analysis. Quantitative angiographic analyses prior to angioplasty and at follow-up showed no significant difference with respect to stenosis progression between the groups. Measurement of neointima formation by histology showed also no significant difference between the groups (0.175+/-0.040 mm(2) vs. 0.123+/-0.075 mm(2)), neither did intimal macrophage count as a marker for local inflammatory response. CONCLUSIONS Despite an increase in plasma glutathione level in the NAC-treated group, there was no reduction in lesion progression after balloon angioplasty. Therefore, NAC does not seem to prevent restenosis after vascular intervention in this animal model.
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Affiliation(s)
- Allen Jeremias
- Department of Internal Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA.
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74
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Alonso A, Lau J, Jaber BL, Weintraub A, Sarnak MJ. Prevention of radiocontrast nephropathy with N-acetylcysteine in patients with chronic kidney disease: a meta-analysis of randomized, controlled trials. Am J Kidney Dis 2004; 43:1-9. [PMID: 14712421 DOI: 10.1053/j.ajkd.2003.09.009] [Citation(s) in RCA: 188] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
BACKGROUND Radiocontrast nephropathy (RCN) is a common cause of hospital-acquired acute renal failure. Results of several studies using N-acetylcysteine (NAC) for the prevention of RCN have yielded conflicting results. We performed a meta-analysis of group data extracted from previously published studies to assess the effect of NAC on the prevention of RCN in patients with pre-existing chronic kidney disease (CKD). METHODS Ovid's multidatabase search for MEDLINE, Cochrane Central Registry of Controlled Trials, Cochrane Database of Systematic Reviews, and HealthSTAR were used to identify candidate articles. Abstracts from proceedings of scientific meetings also were screened. We selected blinded and unblinded randomized controlled trials (RCTs) performed in humans 18 years and older with pre-existing CKD, defined by a mean baseline serum creatinine level of 1.2 mg/dL or greater (> or =106.1 micromol/L) or creatinine clearance less than 70 mL/min (<1.17 mL/s). The overall risk ratio (RR) for the development of RCN was computed using a random-effects model. RESULTS Eight RCTs (n = 885 patients) published in full-text articles were included in the primary analysis. In the control group, the overall rate of RCN was 18.5% (95% confidence interval [CI], 15 to 22). In the primary analysis, overall RR for RCN associated with the use of NAC was 0.41 (95% CI, 0.22 to 0.79; P = 0.007). In a sensitivity analysis that included 4 additional RCTs published in abstract form, RR remained significant at 0.55 (95% CI, 0.34 to 0.91; P = 0.020). CONCLUSION NAC reduces the risk for RCN in patients with CKD.
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Affiliation(s)
- Alvaro Alonso
- Department of Medicine, Division of Nephrology, Tufts-New England Medical Center, Boston, MA 02111, USA
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75
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Hildebrandt W, Hamann A, Krakowski-Roosen H, Kinscherf R, Dugi K, Sauer R, Lacher S, Nöbel N, Bodens A, Bellou V, Edler L, Nawroth P, Dröge W. Effect of thiol antioxidant on body fat and insulin reactivity. J Mol Med (Berl) 2004; 82:336-44. [PMID: 15007512 DOI: 10.1007/s00109-004-0532-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2003] [Accepted: 01/23/2004] [Indexed: 02/07/2023]
Abstract
Insulin signaling is enhanced by moderate concentrations of reactive oxygen species (ROS) and suppressed by persistent exposure to ROS. Diabetic patients show abnormally high ROS levels and a decrease in insulin reactivity which is ameliorated by antioxidants, such as N-acetylcysteine (NAC). A similar effect of NAC has not been reported for non-diabetic subjects. We now show that the insulin receptor (IR) kinase is inhibited in cell culture by physiologic concentrations of cysteine. In two double-blind trials involving a total of 140 non-diabetic subjects we found furthermore that NAC increased the HOMA-R index (derived from the fasting insulin and glucose concentrations) in smokers and obese patients, but not in nonobese non-smokers. In obese patients NAC also caused a decrease in glucose tolerance and body fat mass. Simultaneous treatment with creatine, a metabolite utilized by skeletal muscle and brain for the interconversion of ADP and ATP, reversed the NAC-mediated increase in HOMA-R index and the decrease in glucose tolerance without preventing the decrease in body fat. As the obese and hyperlipidemic patients had lower plasma thiol concentrations than the normolipidemic subjects, our results suggest that low thiol levels facilitate the development of obesity. Supplementation of thiols plus creatine may reduce body fat without compromising glucose tolerance.
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Affiliation(s)
- Wulf Hildebrandt
- Division of Immunochemistry, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
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76
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Affiliation(s)
- Killian Robinson
- Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem, NC 27157-3001, USA.
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77
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Kinscherf R, Cafaltzis K, Röder F, Hildebrandt W, Edler L, Deigner HP, Breitkreutz R, Feussner G, Kreuzer J, Werle E, Michel G, Metz J, Dröge W. Cholesterol levels linked to abnormal plasma thiol concentrations and thiol/disulfide redox status in hyperlipidemic subjects. Free Radic Biol Med 2003; 35:1286-92. [PMID: 14607527 DOI: 10.1016/j.freeradbiomed.2003.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Treatment of hyperlipidemic patients with the thiol compound N-acetylcysteine (NAC) was previously shown to cause a significant dose-related increase in the high-density lipoprotein (HDL)-cholesterol serum level, suggesting the possibility that its disease-related decrease may result from a diminished thiol concentration and/or thiol/disulfide redox status (REDST) in the plasma. We therefore investigated plasma thiol levels and REDST in normo-/hyperlipidemic subjects with and without coronary heart disease (CHD). The thiol level, REDST, and amino acid concentrations in the plasma and intracellular REDST of peripheral blood mononuclear cells (PBMC) have been determined in 62 normo- and hyperlipidemic subjects. Thirty-three of these subjects underwent coronary angiography, because of clinical symptoms of CHD. All groups of hyperlipidemic patients under test and those normolipidemic individuals with documented coronary stenoses showed a marked decrease in plasma thiol concentrations, plasma and intracellular REDST of PBMCs, and a marked increase in plasma taurine levels. Individual plasma thiol concentrations and plasma REDST were strongly negatively correlated with the serum LDL-cholesterol and positively correlated with the serum HDL-cholesterol level. Together with the earlier report about the effect of NAC on the HDL-cholesterol serum level, our findings suggest strongly that lower HDL-cholesterol serum levels may result from a decrease in plasma thiol level and/or REDST possibly through an excessive cysteine catabolism into taurine.
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Affiliation(s)
- Ralf Kinscherf
- Department of Anatomy and Cell Biology III, Heidelberg University, Heidelberg, Germany.
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78
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Fischer UM, Cox CS, Allen SJ, Stewart RH, Mehlhorn U, Laine GA. The antioxidant N-acetylcysteine preserves myocardial function and diminishes oxidative stress after cardioplegic arrest. J Thorac Cardiovasc Surg 2003; 126:1483-8. [PMID: 14666023 DOI: 10.1016/s0022-5223(03)00792-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Oxidative stress contributes to myocardial ischemia-reperfusion injury. We hypothesized that administration of the antioxidant N-acetylcysteine would have beneficial effects on myocardial function after cardiopulmonary bypass and cardioplegic arrest. METHODS Anesthetized dogs (n = 18) were instrumented with myocardial ultrasonic crystals and a left ventricular micromanometer. Systolic function was measured by preload recruitable stroke work. Myocardial tissue water was determined by microgravimetry. Treated animals received 100 mg.kg(-1) N-acetylcysteine 10 minutes before initiation of cardiopulmonary bypass followed by 20 mg.kg(-1).h(-1) continuous infusion until 1 hour after cardiopulmonary bypass. After baseline, cardiopulmonary bypass and 2-hour crystalloid cardioplegic arrest was initiated, then reperfusion/rewarming for 40 minutes and separation from cardiopulmonary bypass. Myocardial function parameters and myocardial tissue water were measured at 30, 60, and 120 minutes after cardiopulmonary bypass. Oxidative stress was measured by 8-isoprostane concentrations in the coronary sinus plasma. RESULTS Preload recruitable stroke work did not decrease from baseline in the N-acetylcysteine group and was significantly greater in N-acetylcysteine group compared with controls at 30 (104% +/- 9% vs 80% +/- 4%; P <.05) and 120 minutes (98% +/- 7% vs 79% +/- 4%; P <.05) after cardiopulmonary bypass. Concentrations of 8-isoprostane in the coronary sinus plasma of the control dogs were significantly higher 30 minutes after cardiopulmonary bypass compared with baseline but were unchanged in the N-acetylcysteine group. Myocardial edema resolution was significantly greater in the N-acetylcysteine group at 30 minutes after cardiopulmonary bypass compared with control (-2.5% +/- 0.7% vs -0.3% +/- 0.5% myocardial tissue water; P <.05). CONCLUSIONS Administration of the antioxidant N-acetylcysteine preserves systolic function and enhances myocardial edema resolution after cardiopulmonary bypass/cardioplegic arrest. Furthermore, oxidative stress was significantly reduced in the treated animals. Therefore, our findings support the hypothesis that oxidative stress is the main cause for myocardial dysfunction after ischemia-reperfusion.
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Affiliation(s)
- Uwe M Fischer
- Center for Microvascular and Lymphatic Studies, Department of Surgery and Anesthesiology, the University of Texas-Houston Medical School, USA.
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79
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Medved I, Brown MJ, Bjorksten AR, Leppik JA, Sostaric S, McKenna MJ. N-acetylcysteine infusion alters blood redox status but not time to fatigue during intense exercise in humans. J Appl Physiol (1985) 2003; 94:1572-82. [PMID: 12496140 DOI: 10.1152/japplphysiol.00884.2002] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Infusion of the antioxidant N-acetylcysteine (NAC) reduces fatigability in electrically evoked human muscle contraction, but due to reported adverse reactions, no studies have investigated NAC infusion effects during voluntary exercise in humans. We investigated whether a modified NAC-infusion protocol (125 mg. kg(-1). h(-1) for 15 min, then 25 mg. kg(-1). h(-1)) altered blood redox status and enhanced performance during intense, intermittent exercise. Eight untrained men participated in a counterbalanced, double-blind, crossover study in which they received NAC or saline (control) before and during cycling exercise, which comprised three 45-s bouts and a fourth bout that continued to fatigue, at 130% peak oxygen consumption. Arterialized venous blood was analyzed for glutathione status, hematology, and plasma electrolytes. NAC infusion induced no severe adverse reactions. Exercise decreased the reduced glutathione (P < 0.005) and increased oxidized glutathione concentrations (P < 0.005); NAC attenuated both effects (P < 0.05). NAC increased the rise in plasma K(+) concentration-to-work ratio (P < 0.05), indicating impaired K(+) regulation, although time to fatigue was unchanged (NAC 102 +/- 45 s; saline 107 +/- 53 s). Thus NAC infusion altered blood redox status during intense, intermittent exercise but did not attenuate fatigue.
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Affiliation(s)
- I Medved
- Muscle, Ions, and Exercise Group, Centre for Rehabilitation, Exercise, and Sport Science, School of Human Movement, Recreation, & Performance, Victoria University of Technology, Victoria, Australia 8001
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Tepel M, van der Giet M, Statz M, Jankowski J, Zidek W. The antioxidant acetylcysteine reduces cardiovascular events in patients with end-stage renal failure: a randomized, controlled trial. Circulation 2003; 107:992-5. [PMID: 12600912 DOI: 10.1161/01.cir.0000050628.11305.30] [Citation(s) in RCA: 264] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Patients with end-stage renal failure have increased oxidative stress and show elevated cardiovascular mortality. Whether increased cardiovascular events can be prevented by the administration of antioxidants is unknown. METHODS AND RESULTS We evaluated the effects of acetylcysteine, a thiol-containing antioxidant, on cardiovascular events in patients undergoing hemodialysis. A prospective, randomized, placebo-controlled trial was conducted between October 1, 1999, and September 30, 2001, in 134 patients (76 male and 58 female) with a mean age of 62+/-16 years (mean+/-SD) who had been undergoing maintenance hemodialysis for a minimum of 3 months 3 times weekly in an ambulatory center. Median (range) follow-up was 14.5 (1 to 24) months. Patients were randomly assigned either to receive acetylcysteine (600 mg BID) or placebo. The primary end point was a composite variable consisting of cardiac events including fatal and nonfatal myocardial infarction, cardiovascular disease death, need for coronary angioplasty or coronary bypass surgery, ischemic stroke, peripheral vascular disease with amputation, or need for angioplasty. Secondary end points included each of the component outcomes, total mortality, and cardiovascular mortality. A total of 18 (28%) of the 64 hemodialysis patients assigned to acetylcysteine group and 33 (47%) of the 70 hemodialysis patients assigned to control group had a primary end point (relative risk, 0.60 [95% CI, 0.38 to 0.95], P=0.03). No significant differences in secondary end points or total mortality were detected. CONCLUSIONS In hemodialysis patients, treatment with acetylcysteine (600 mg BID) reduces composite cardiovascular end points.
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Affiliation(s)
- Martin Tepel
- Med Klinik IV, Univ.-Klinik Benjamin Franklin, Freie Universität Berlin, Germany.
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81
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Abstract
Endothelial dysfunction is a systemic disorder and a key variable in the pathogenesis of atherosclerosis and its complications. Current evidence suggests that endothelial status is not determined solely by the individual risk factor burden but rather, may be regarded as an integrated index of all atherogenic and atheroprotective factors present in an individual, including known as well as yet-unknown variables and genetic predisposition. Endothelial dysfunction reflects a vascular phenotype prone to atherogenesis and may therefore serve as a marker of the inherent atherosclerotic risk in an individual. In line with this hypothesis, dysfunction of either the coronary or peripheral vascular endothelium was shown to constitute an independent predictor of cardiovascular events, providing valuable prognostic information additional to that derived from conventional risk factor assessment. Interventions like risk factor modification and treatment with various drugs, including statins and angiotensin-converting enzyme inhibitors, may improve endothelial function and thereby, potentially prognosis. Hence, given its reversibility and granted the availability of a diagnostic tool to identify patients at risk and to control the efficacy of therapy in clinical practice, endothelial dysfunction may be an attractive primary target in the effort to optimize individualized therapeutic strategies to reduce cardiovascular morbidity and mortality.
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Affiliation(s)
- Piero O Bonetti
- Center for Coronary Physiology and Imaging, Department of Internal Medicine, Mayo Clinic and Foundation, Rochester, MN 55905, USA
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82
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Dröge W. Aging-related changes in the thiol/disulfide redox state: implications for the use of thiol antioxidants. Exp Gerontol 2002; 37:1333-45. [PMID: 12559403 DOI: 10.1016/s0531-5565(02)00175-4] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Genetic and biochemical studies suggest that free radical-derived reactive oxygen species play a key role in a common mechanism of aging in many or all animal species. This led to the hypothesis that the quality of life in old age may be improved by pharmacological or dietary thiol antioxidants. This review describes important details about how the organism deals with its own thiol antioxidants. Aging was found to be associated with an oxidative shift in the thiol/disulfide redox state (REDST) of the intracellular glutathione pool and of the plasma cyst(e)ine and albumin pools. There is also a decrease in plasma thiol (mainly cysteine) concentration. The oxidative shift in intracellular REDST was found to be typically associated with cellular dysfunctions. Studies in humans related to plasma REDST revealed correlations with aging-related pathophysiological processes, suggesting that oxidative changes in REDST play a key role in processes and diseases which limit the human life span. The age-related shift in plasma REDST is mediated, at least partly, by the decreasing capacity to remove dietary cysteine from the oxidative environment of the blood. Thiol antioxidants were found to ameliorate various aging-related processes but obviously ought to be used with caution in consideration of the oxidative environment of the blood.
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Affiliation(s)
- Wulf Dröge
- Deutsches Krebsforschungszentrum, German Cancer Research Center (DKFZ), Division of Immunochemistry, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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83
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Miscellaneous medications for the management of atherosclerosis: Mayhem or miracle? Semin Vasc Surg 2002. [DOI: 10.1016/s0895-7967(02)70027-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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84
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Evans JL, Goldfine ID, Maddux BA, Grodsky GM. Oxidative stress and stress-activated signaling pathways: a unifying hypothesis of type 2 diabetes. Endocr Rev 2002; 23:599-622. [PMID: 12372842 DOI: 10.1210/er.2001-0039] [Citation(s) in RCA: 1428] [Impact Index Per Article: 64.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In both type 1 and type 2 diabetes, the late diabetic complications in nerve, vascular endothelium, and kidney arise from chronic elevations of glucose and possibly other metabolites including free fatty acids (FFA). Recent evidence suggests that common stress-activated signaling pathways such as nuclear factor-kappaB, p38 MAPK, and NH2-terminal Jun kinases/stress-activated protein kinases underlie the development of these late diabetic complications. In addition, in type 2 diabetes, there is evidence that the activation of these same stress pathways by glucose and possibly FFA leads to both insulin resistance and impaired insulin secretion. Thus, we propose a unifying hypothesis whereby hyperglycemia and FFA-induced activation of the nuclear factor-kappaB, p38 MAPK, and NH2-terminal Jun kinases/stress-activated protein kinases stress pathways, along with the activation of the advanced glycosylation end-products/receptor for advanced glycosylation end-products, protein kinase C, and sorbitol stress pathways, plays a key role in causing late complications in type 1 and type 2 diabetes, along with insulin resistance and impaired insulin secretion in type 2 diabetes. Studies with antioxidants such as vitamin E, alpha-lipoic acid, and N-acetylcysteine suggest that new strategies may become available to treat these conditions.
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Affiliation(s)
- Joseph L Evans
- University of California at San Francisco, San Francisco, California 94143, USA.
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85
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Abstract
PURPOSE OF REVIEW Radiographic contrast media are used at an increasing rate for several diagnostic and therapeutic applications. Therefore, contrast agent-induced nephropathy will become more important, including the risk of patient impairment and costs. The prevention of radiographic contrast-induced nephropathy is mandatory. Radiographic contrast agent-induced nephropathy is caused by vasoconstriction-mediated renal medullary ischaemia and direct toxic damage to renal tubular epithelial cells. These effects may be partly mediated by the generation of reactive oxygen species. Data from experimental studies indicate that antioxidants, e.g. acetylcysteine, may prevent radiocontrast-induced nephropathy. RECENT FINDINGS Two prospective, randomized, placebo-controlled studies in patients with moderate renal insufficiency confirmed that the prophylactic oral administration of acetylcysteine, at a dose of 600 mg twice a day along with hydration, prevents the reduction in renal function after radiocontrast administration. SUMMARY The use of acetylcysteine together with hydration is the treatment of choice to protect against radiographic contrast media-induced nephropathy.
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Affiliation(s)
- Martin Tepel
- Medizinische Klinik IV, Universitätsklinikum Benjamin-Franklin, Freie Universität, Berlin, Germany.
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86
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Briguori C, Manganelli F, Scarpato P, Elia PP, Golia B, Riviezzo G, Lepore S, Librera M, Villari B, Colombo A, Ricciardelli B. Acetylcysteine and contrast agent-associated nephrotoxicity. J Am Coll Cardiol 2002; 40:298-303. [PMID: 12106935 DOI: 10.1016/s0735-1097(02)01958-7] [Citation(s) in RCA: 263] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Prophylactic acetylcysteine along with hydration seems to be better than hydration alone in preventing the reduction in renal function induced by a contrast dye. BACKGROUND Contrast media can lead to acute renal failure that may occasionally require hemodialysis. METHODS One hundred eighty-three consecutive patients with impairment of renal function, undergoing coronary and/or peripheral angiography and/or angioplasty, were randomly assigned to receive 0.45% saline intravenously and acetylcysteine (600 mg orally twice daily; group A, n = 92) or 0.45% saline intravenously alone (group B, n = 91) before and after nonionic, low-osmolality contrast dye administration. RESULTS The baseline serum creatinine concentrations were similar (1.5 +/- 0.4 mg/dl in group A vs. 1.5 +/- 0.4 mg/dl in group B; p = 0.37). An increase of > or =25% in the baseline creatinine level 48 h after the procedure occurred in 6 (6.5%) of 92 patients in group A and in 10 (11%) of 91 patients in group B (p = 0.22). In the subgroup with a low (<140 ml) contrast dose, renal function deterioration occurred in 5 (8.5%) of 60 patients in group B and in 0 of 60 patients in group A (p = 0.02; odds ratio [OR] 0.44, 95% confidence interval [CI] 0.35 to 0.54). In the subgroup with a high contrast dose, no difference was found (5/31 vs. 6/32 patients, p = 0.78). By multivariate analysis, the amount of contrast agent, but not the treatment strategy, was a predictor of the occurrence of contrast dye-associated nephrotoxicity (OR 2.58, 95% CI 1.1 to 4.9; p = 0.035). CONCLUSIONS In patients with reduced renal function undergoing angiography and/or angioplasty, the amount of contrast agent, but not the administration of prophylactic acetylcysteine, was a predictor of renal function deterioration. Prophylactic acetylcysteine might provide better protection than hydration alone, only when a small volume of contrast agent is used.
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Affiliation(s)
- Carlo Briguori
- Laboratory of Interventional Cardiology and Department of Cardiology, Clinica Mediterranea, Via Orazio 2, I-80121 Naples, Italy.
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87
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Roes EM, Raijmakers MTM, Peters WHM, Steegers EAP. Effects of oral N-acetylcysteine on plasma homocysteine and whole blood glutathione levels in healthy, non-pregnant women. Clin Chem Lab Med 2002; 40:496-8. [PMID: 12113295 DOI: 10.1515/cclm.2002.086] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Oral N-acetylcysteine supplementation in nine young healthy females induced a quick and highly significant decrease in plasma homocysteine levels and an increase in whole blood concentration of the antioxidant glutathione. N-acetylcysteine impresses as an efficient drug in lowering homocysteine concentration and might be beneficial for individuals with hyperhomocysteinemia who are at increased risk of cardiovascular disease.
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Affiliation(s)
- Eva Maria Roes
- Department of Obstetrics and Gynecology, University Medical Centre, Nijmegen, The Netherlands
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88
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Sochman J. N-acetylcysteine in acute cardiology: 10 years later: what do we know and what would we like to know?! J Am Coll Cardiol 2002; 39:1422-8. [PMID: 11985902 DOI: 10.1016/s0735-1097(02)01797-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
N-acetylcysteine (NAC) is known in a variety of branches of medicine. This paper addresses in detail the action of NAC as it is emerging from research and clinical trials over the past decade in cardiology, giving rise to new concepts. The result is a process resembling creation of a mosaic from individual pieces. Also, the role of NAC in acute cardiology, during acute reperfusion in particular, is defined.
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Affiliation(s)
- Jan Sochman
- Intensive care Unit, Institute for Clinical and Experimental Medicine, Prague, Czech
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89
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Hildebrandt W, Kinscherf R, Hauer K, Holm E, Dröge W. Plasma cystine concentration and redox state in aging and physical exercise. Mech Ageing Dev 2002; 123:1269-81. [PMID: 12020948 DOI: 10.1016/s0047-6374(02)00013-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Because redox-regulated signalling pathways are often modulated by the thiol/disulfide redox state (REDST), changes in plasma REDST may possibly account for pathological processes. We, therefore, investigated the mechanisms that account for changes in the plasma REDST as derived in first approximation from the cystine and acid soluble thiol (mainly cysteine) concentrations. Elderly subjects (studies A) and younger subjects after intensive physical exercise (IPE) (study B) i.e. subjects in conditions typically associated with decreased insulin responsiveness, showed, on the average, an increase in the plasma total free amino acid (TAA) concentration to approximately 3000 microM, including an increase in cystine but no increase in the thiol concentration if compared with controls. The REDST was decreased accordingly. A study on the postabsorptive amino acid exchange rates across the lower extremities (study C) indicated that a TAA level > or =2800 microM supports a balanced net protein synthesis even under conditions of weak insulin stimulation, suggesting that high TAA levels may prevent the release of cysteine into the blood in the postabsorptive state. Collectively, these studies indicate that the age-related oxidative shift in plasma REDST may result from the decrease in amino acid clearance capacity and may be aggravated by excessive physical exercise.
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Affiliation(s)
- W Hildebrandt
- Department of Immunochemistry, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
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90
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Abstract
Radiocontrast nephropathy may in part be mediated by generation of reactive oxygen species causing direct toxic damage to renal tubular epithelial cell and renal medullary ischemia. Data from experimental studies indicated that antioxidants, eg, acetylcysteine, may prevent radiocontrast-induced nephropathy. Recently, one prospective, randomized, placebo-controlled study in patients with moderate renal insufficiency confirmed that the prophylactic oral administration of acetylcysteine at a dose of 600 mg twice daily along with hydration prevents the reduction in renal function by a nonionic, low-osmolality radiocontrast agent.
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Affiliation(s)
- M Tepel
- Medical Klinik IV, Universitätsklinikum Benjamin-Franklin, Freie Universität Berlin, Germany
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91
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Ytrebø LM, Korvald C, Nedredal GI, Elvenes OP, Nielsen Grymyr OJ, Revhaug A. N-acetylcysteine increases cerebral perfusion pressure in pigs with fulminant hepatic failure. Crit Care Med 2001; 29:1989-95. [PMID: 11588469 DOI: 10.1097/00003246-200110000-00023] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Intravenous administration of N-acetylcysteine beyond 15 hrs reduces mortality rates in patients suffering from paracetamol-induced fulminant hepatic failure, although the mechanism of the therapeutic benefit remains unclear. We hypothesized increased survival to be caused by improved hemodynamic performance. The main objective for the study was to explore the effect of N-acetylcysteine on hemodynamics, oxygen transport, and regional blood flow in pigs with fulminant hepatic failure. DESIGN Prospective, randomized, controlled trial. SETTING Surgical research laboratory in a university hospital. SUBJECTS Female Norwegian Landrace pigs. INTERVENTIONS Fulminant hepatic failure was induced by a total liver devascularization procedure. Five hours later, the pigs were allocated to N-acetylcysteine treatment (150 mg.kg-1 in 100 mL of 0.9% saline over 15 mins, followed by 50 mg.kg-1 in 500 mL of 0.9% saline over a period of 4 hrs) or placebo. MEASUREMENTS AND MAIN RESULTS Mean arterial pressure stabilized in the N-acetylcysteine group and increased slightly during the last 2 hrs (pGT =.009). Thus, mean arterial pressure was significantly higher compared with placebo after 3 hrs (p =.01). Cerebral perfusion pressure was significantly higher during the last 2 hrs in the N-acetylcysteine group (pGT =.033). Common carotid artery flow also increased and was maintained at a higher level compared with placebo (pG =.027). Systemic vascular resistance index initially decreased but then gradually increased (pGT <.001). Cardiac index increased after 15 mins of N-acetylcysteine infusion, causing a significant interaction (pGT =.038), but did not differ after 3 hrs. No significant differences in hindleg and mesentery hemodynamics were found. A short-lived increase in oxygen delivery caused by a temporary increase in cardiac index was observed but without any corresponding increase in oxygen consumption. CONCLUSIONS Intravenous N-acetylcysteine infusion increases cerebral perfusion pressure in pigs with fulminant hepatic failure. Earlier reported effects on oxygen transport and uptake could not be confirmed.
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Affiliation(s)
- L M Ytrebø
- Department of Digestive Surgery, Tromsø University Hospital, N-9038 Tromsø, Norway
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