Spontaneous superoxide formation by human neutrophils of patients with stable angina after physical exercise*1 (original) (raw)
Occurrence of oxidative stress during reperfusion of the human heart
Circulation, 1990
We have investigated the relation between occurrence of myocardial oxidative stress and functional recovery during postischemic reperfusion in 20 selected patients subjected to aortocoronary bypass grafting. Patients were selected for having normal percent ejection fraction and left ventricular end-diastolic pressure before the operation. Occurrence of oxidative stress was assessed by measuring the formation and release of oxidized glutathione (GSSG) in the coronary sinus immediately before aortic cross-clamp, 1, 5, 10, and 20 minutes after removal of aortic cross-clamp, and 10 and 20 minutes after the end of cardiopulmonary bypass. Reduced glutathione (GSH), lactate, and creatine phosphokinase release were also monitored with the same timing. Standard hemodynamic measurements were recorded by means of a triple-lumen thermodilution pulmonary artery catheter before sternotomy, 15 minutes after the end of cardiopulmonary bypass, and during the 24 hours after termination of cardiopulmona-ry bypass. Reperfusion in patients after a short period of ischemia (less than 30 minutes; group 1) resulted in a small and transient release in the coronary sinus of GSSG and GSH and in a progressive improvement of hemodynamic parameters reaching a stable state 4 hours after the operation. In patients with a period of ischemia longer than 30 minutes (group 2), reperfusion induced a marked and sustained release of lactate, GSH, and GSSG; the arteriocoronary sinus difference for GSSG was still negative after the end of cardiopulmonary bypass. The arteriocoronary sinus difference for creatine phosphokinase also remained negative for as long as 20 minutes after cardiopulmonary bypass, and the rate of functional recovery was significantly delayed, reaching the values of group 1 only 12 hours after the operation. In these patients there was a positive correlation (r=0.88, p<0.01) between the duration of ischemia and the myocardial arteriovenous difference for GSSG. In addition, there was a negative correlation between the arteriocoronary sinus difference for GSSG and cardiac index measured 2, 4, and 6 hours after the operation. These data suggest for the first time that, depending on the severity of the ischemic period, oxidative stress occurs during reperfusion of patients with coronary artery disease who are subjected to heart surgery and that it may be linked with a delay in postoperative recovery of cardiac function. (Circulation 1990;81:201-211) T nhe availability of techniques such as surgical reperfusion, angioplasty, and thrombolysis for the restoration of blood flow to the ischemic myocardium has revived interest in the molecular events occurring during reperfusion.1-5 It is clear that reperfusion occupies a central role in
Free Radical Research, 2003
The aim of this study was to analyse the level and progression of oxidative stress, in both plasma and erythrocytes, during heart surgery involving cardiopulmonary bypass. Materials and Methods: Twenty two patients undergoing cardiac surgery and considered to present a high/severe level of surgical risk were selected. We took five blood samples at different times during the cardiac surgery and analysed TBARS, a-tocopherol, coenzyme Q and retinol in plasma and TBARS (baseline levels and induced by Fe 2þ-ascorbate oxidation), a-tocopherol, coenzyme Q and catalase, superoxide dismutase and gluthatione peroxidase activity in erythrocytes. Results: Plasma results shown a decrease in both a-tocopherol and retinol concentration after starting CPB with respect to the reference level ð13:6^1:5 nmol ml 21 vs. 22:0^3:0 nmol ml 21 and 1:2^0:1 nmol ml 21 vs. 1:8^0:2 nmol ml 21 ; respectively ðp , 0:05ÞÞ: In comparison, in erythrocytes, all antioxidants, both enzymatic and non-enzymatic, increased in activity or concentration after starting CPB. Erythrocyte TBARS, both baseline levels and induced levels, followed a similar pattern, with an increase after starting CPB with respect to the reference level (3:9^0:6 nmol mg 21 of protein vs. 2:3^0:2 nmol mg 21 of protein and 10:6^0:8 nmol mg 21 of protein vs. 6:7^0:6 nmol mg 21 of protein, respectively ðp , 0:05ÞÞ: Conclusion: These results reveal an increase in oxidative stress after CPB, both in plasma and erythrocytes, and although the organism is capable of attenuating this stress by means of various antioxidative defence mechanisms, there is an increased possibility of post-CPB complications and thus of mortality.
Cardiovascular Research, 2007
Objective: In animal models, formation of oxidants during postischemic reperfusion may exert deleterious effects ("oxidative stress"). Cardioplegic arrest/reperfusion during cardiac surgery might similarly induce oxidative stress. However, the phenomenon has not been precisely characterized in patients, and therefore the role of antioxidant therapy at cardiac surgery is a matter of debate. Thus, we wanted to ascertain whether the relationship between oxidant formation and development of myocardial injury also translates to the situation of patients subjected to cardioplegic arrest. Methods: In 24 patients undergoing coronary artery bypass, trans-cardiac blood samples and myocardial biopsies were taken before cardioplegic arrest and again following reperfusion. Results: Cardiac glutathione release (marker of oxidant production) was negligible at baseline (0.02 ± 0.04 μmol/L), but it increased 15 min into reperfusion (1.10 ± 0.40 μmol/L; p b 0.05); concomitantly, myocardial concentration of the antioxidant ubiquinol decreased from 144.5 ± 52.0 to 97.6 ± 82.0 nmol/g (p b 0.05). Although these changes document cardiac exposure to oxidants, they were not accompanied by evidence of injury. Neither coronary sinus blood nor cardiac biopsies showed increased lipid peroxide concentrations. Furthermore, electron microscopy showed no major ultrastructural alterations. Finally, full recovery of left ventricular systolic and diastolic function was observed. Conclusions: Careful investigation reveals that while oxidant production does occur during cardiac surgery in patients with chronic ischemic heart disease, cardiac oxidative stress may not progress through membrane damage and irreversible injury.
Heart, 1998
Objective-To determine whether preoperative left ventricular ejection fraction (LVEF) is related to the degree of myocardial oxidative stress during bypass surgery in man. Design-Observational study. Setting-Tertiary care centre. Patients and interventions-31 patients (LVEF range was 20% to 68%) undergoing elective coronary bypass surgery with blood cardioplegic reperfusion were studied. Arterial and coronary sinus blood was collected before aortic cross clamping (T0) and at 0 (T1), 15 (T2), and 30 (T3) minutes after unclamping. Transmural left ventricular biopsies were also obtained from 15 patients at T0 and at T1. Main outcome measures-Glutathione and adenine nucleotides were measured in myocardial biopsies, while coronary sinus-artery diVerences for glutathione, nucleotides, and products of lipid peroxidation were calculated from blood specimens. Creatine kinase (myocardial band; CK-MB) was measured in plasma at four and 12 hours after operation. Results-Myocardial glutathione and adenine nucleotides were correlated (p < 0.02) with preoperative LVEF both at T0 (r = 0.909 and 0.672) and T1 (r = 0.603 and 0.605). Oxidised glutathione released from the heart during reperfusion was inversely correlated with LVEF (r = -0.448, -0.466, and -0461 at T1, T2, and T3, p < 0.01), while reduced glutathione (r = 0.519 and 0.640 at T1 and T2) and glutathione redox ratio (r = 0.647, 0.714, 0.645, and 0.702 at T0, T1, T2, and T3) showed a direct correlation (p < 0.01). Lipid peroxidation at T1 was negatively related to LVEF (r = -0.492). CK-MB was also negatively related to LVEF (r = -0.440 at 4 h and -0.462 at 12 h). Conclusions-The capacity to counterbalance oxidative burst following ischaemia and reperfusion appears to be related to the functional ability of the heart.
Myocardial release of malondialdehyde and purine compounds during coronary bypass surgery
Circulation, 1994
Background Free radicals and lipid peroxidation have been suggested to play an important role in the pathophysiology of myocardial reperfusion injury. The purpose of the present study was to monitor myocardial malondialdehyde (MDA) production as an index of lipid peroxidation during ischemia- reperfusion sequences in patients undergoing elective coro- nary bypass grafting. There has been a lot of debate on the role of xanthine oxidase as a potential superoxide anion generator and thus lipid peroxidation in human myocardium. To evalu- ate the activity of xanthine oxidase pathway, we measured the changes in the transcardiac concentration differences in adenosine, inosine, hypoxanthine, xanthine, and uric acid. Methods and Results The coronary sinus-aortic root differ- ences (CS-Ao) of MDA, oxypurines, and nucleosides were measured by a recently developed ion-pairing high-performance liquid chromatographic (HPLC) method. Fifteen pa- tients were included in the study, and 13 of them demonstrated a more than 10-fold increase in net myocardial production of MDA on intermittent reperfusion during the aortic cross- clamp period. In 2 patients, MDA was not detectable in any of the CS or Ao samples. Before aortic cross-clamping, the CS-Ao concentration differences in adenosine, inosine, hypoxanthine, xanthine, and uric acid were 0.59+0.19, 0.23+±0.05, eperfusion of ischemic myocardium is clinically R encountered during thrombolytic treatment of acute myocardial infarction, coronary angio- plasty, and bypass surgery as well as during cardiac transplantation. Although basically beneficial, reperfusion has been shown to be associated with tissue damage, development of postischemic dysfunction (stunning) of the myocardium, and reperfusion arrhythmias.1-5 Studies with experimental animals have emphasized the role of free radicals and lipid peroxidation in the pathophysiology of reperfusion injury and myocardial stunning.3'6-10 Reper-
Biomedicine & Pharmacotherapy, 2002
Myocardial and endothelial damage is still a widely debated problem during the ischemia-reperfusion sequence in heart surgery. We evaluated myocardial purine metabolites, antioxidant defense mechanisms, oxidative status and endothelial dysfunction markers in 14 patients undergoing coronary artery bypass graft (CABG). Heart biopsies were taken before aortic cross-clamping (t1), before clamp removal (t2) and 30 min after reperfusion (t3); perchloric extracts of the tissue were analyzed for glutathione, NAD, nucleotide nucleoside and base content by capillary electrophoresis (CE). In plasma samples from the coronary sinus we evaluated: nitrate and nitrite concentrations by CE, plasma glutathione peroxidase (plGPx) by ELISA, endothelin-1 (ET-1) by RIA and reactive oxygen metabolites (ROM) by colorimetric assay. During the ischemic period (t2) we observed a reduction in cellular NAD and GSH levels, as well as nitrate, nitrite and plGPx. ATP and GTP levels decreased and their catabolic products AMP, GMP, IMP, adenosine, inosine and hypoxanthine accumulated. The energy charge, ATP/ADP ratio, and nucleotide/(nucleoside + base) ratios decreased. At t3, levels of plasma ET-1 increased and monophosphate nucleotides tended to return to basal values. The energy charge did not increase but the nucleotide/(nucleoside + nucleobase) ratio recovered to some extent. Levels of nitrates plus nitrites continued to decrease. No significant variation in ROM levels was observed. Our data indicate that oxidative stress and endothelial damage are major events during CABG, overwhelming the scavenging capacity of the myocyte and preventing restoration of the normal energy balance for 30 min after reperfusion. The AMP deaminase pathway leading to IMP production is active during ischemia and adenosine is not the main compound derived from ATP breakdown in the human heart. The possible role of extracorporeal circulation is also discussed.
Antioxidant defence during cardiopulmonary bypass surgery
2010
Objective: Cardiac surgery may lead to severe oxidative stress due to formation of oxidation products generated during ischemia and reperfusion. We investigated to which extent oxidative stress influences a number of endogenous antioxidants and markers of cellular activation. Methods: At six time points blood was withdrawn from patients undergoing coronary artery bypass grafting, using the on-pump procedure. Results: Both glutathione peroxidase and superoxide dismutase show a gradual and strong increase in activity during surgery (40 and 30%, respectively), returning to baseline values 24 h after surgery. The total antioxidant capacity has a maximum increase of 60%. Markers of cellular activation, such as eosinophil cationic protein and tryptase also increase during the procedure. Conclusion: Cardiac surgery results in systemic inflammation accompanied or caused by severe oxidative stress. The human body has a strong innate oxidative defence screen, which is probably not sufficient to fully compensate for the total amount of oxidative damage. q
Objectives: To determine whether oxidative stress occurs in unstable angina and to examine the state of oxidative stress during reperfusion state following myocardial infarction and bouts of recurrent ischemia in unstable angina. Methods: Blood samples were taken from 16 with acute myocardial infarction (AMI), 11 with unstable angina (UA) and 34 healthy volunteers. The concentration of plasma and neutrophil SOD, catalase, MDA, ceruloplasmin, Cu+2, Zn+2 and thiols were etermined at first and seventh day of onset of chest pain following complete clinical response. Results: The means of serum total creatine phosphokinase enzyme activity and the neutrophil count were significantly increased (P<0.001) with increase in both plasma Cu+2 and ceruloplasmin concentration (P<0.01) and significant decrease in the mean neutrophil SOD activity in AMI group within the first day of onset of chest pain in comparison to the control mean values ( P<0.05). The means of plasma Cu+2, and neutrophil Cu+2 were increased by 26.8, and 13.7%, respectively after seven days of onset of chest pain (P < 0.01) in UA group. The activity of neutrophils catalase revealed 14% decrease in UA at day seven as compared to those of the first day of chest pain. In AMI group, the catalase activities showed a near significant reduction (18.4, P < 0.07), on the seventh day, while the mean of SOD activities was significantly increased to 8.4% over the first day reported mean enzyme activity (P < 0.01). Significant decrease in thiols and MDA (10.3% , 22.6%.P<0.01) in UA and MDA values was increased in AMI to 25.7% (P<0.01) as compared to the day one mean concentration. Conclusion: There was more alleviation in the oxidative stress effect (MDA and thiols, SOD, catalase, ceruloplasmin) in UA as compared to AMI at reperfusion state.
Increased NAD(P)H Oxidase and Reactive Oxygen Species in Coronary Arteries After Balloon Injury
Reactive oxygen species (ROS), produced by cellular constituents of the arterial wall, provide a signaling mechanism involved in vascular remodeling. Because adventitial fibroblasts are actively involved in coronary remodeling, we examined whether the changes in the redox state affect their phenotypic characteristics. To this end, superoxide anion production and NAD(P)H oxidase activity were measured in porcine coronary arteries in vivo, and the effect of ROS generation on adventitial fibroblast proliferation was examined in vitro. Superoxide production (SOD-and Tiron-inhibitable nitro blue tetrazolium [NBT] reduction) increased significantly within 24 hours after balloon-induced injury, with the product of NBT reduction present predominantly in adventitial fibroblasts. These changes were NAD(P)H oxidase-dependent, because diphenyleneiodonium (DPI) abolished superoxide generation (PϽ0.001). Furthermore, the injury-induced superoxide production was associated with augmented NAD(P)H oxidase activity and upregulation of p47 phox and p67 phox in adventitial fibroblasts (immunohistochemistry). Serum stimulation of isolated adventitial fibroblasts produced time-dependent increases in ROS production (peak 3 to 6 hours). The inhibition of ROS generation with NAD(P)H oxidase inhibitor (DPI) or the removal of ROS with antioxidants (Tiron, catalase) abrogated proliferation of adventitial fibroblasts. These results indicate that vascular NAD(P)H oxidase plays a central role in the upregulation of oxidative stress after coronary injury, providing pivotal growth signals for coronary fibroblasts. (Arterioscler Thromb Vasc Biol. 2001;21:739-745.)
Acta Anaesthesiologica Scandinavica, 2007
Background: In experimental studies, exposure to hyperoxia for a limited time before ischaemia induces a low-grade systemic oxidative stress and evokes an (ischaemic) preconditioning-like effect of the myocardium. We hypothesised that hyperoxia before cardioplegia could protect the myocardium against necrosis and stunning caused by ischaemia-reperfusion. Methods: Forty patients undergoing coronary artery bypass grafting were randomly exposed to an oxygen fraction of 0.4 or >0.96 in inspired air on an average of 120 min before cardioplegia. Blood for troponin I, creatine kinase-MB, lactate, glutathione and interleukin-6 was sampled from arterial and coronary sinus cannulae during 20 min of reperfusion. Additional arterial samples were drawn 60 min after declamping and in the first postoperative morning. The cardiac index and right and left ventricular stroke work indices were measured before sternotomy and up to 12 h post-operatively. Results: Troponin I, creatine kinase-MB and lactate did not differ between the groups. Hyperoxic pre-treatment had no impact on the post-operative haemodynamic indices measured with the thermodilution pulmonary artery catheter. More oxidised gluta-thione was released in the hyperoxia group in the first minute of reperfusion (P ¼ 0.015). Hyperoxic pre-treatment abolished the myocardial release of interleukin-6 during 20 min of reperfusion (P ¼ 0.021 vs. controls). In the first post-operative morning, interleukin-6 was higher in the hyperoxia group [127.0 (86.0-140.0) vs. 85.2 pg/ml (66.6-94.5 pg/ml); P ¼ 0.016]. Conclusions: Exposure to >96% oxygen before cardioplegia did not attenuate ischaemia-reperfusion injury of the heart in patients undergoing coronary artery bypass grafting. The only potentially beneficial effect observed was the decreased transmyocardial release of interleukin-6.
Acta Anaesthesiologica Scandinavica, 1995
In experimental animal models reperfiision of ischaemic myocardium causes sequestration of leucocytes within the coronary circulation. Leucocytes contribute to postischaemic myocardial injury by releasing proteolytic cnzymes and by generating oxygen free radicals. The aim of this study was to investigate whether Icucocytrs also contribute to myocardial injury following ischaemia and reperfiision associated with cardioplegic cardiac arrcst. Therefore, we studied the release of the proteolytic enLynie elastase and oxysen free radical initiatcd myocardial lipid peroxidation in coronary sinus blood duriiig reperfusion after cardioplegc cardiac arrcst. The elastasealpha-1-proteinase inhibitor complex and malondialdehyde (a byproduct of myocardial lipid peroxidation) wcrc measured in arterial, central venous and coronary sinus blood samples in I9 patients undergoing elective coroiiaiy artery bypass grafting hefore aortic crossclamping and I , 5, 10 and 20 min after aortic declamping. Malondialdehyde concentrations did not increasc significantly during the study period, whereas elastasc concentrations showed a significant increase during cardiopulmonary bypass in artcrial, central vrn(xis as well as coronary sinus blood. Neither elastase nor malondialhydc concentrations in coronary sinus blood differed significantly from arterial or central vcnous blood at any time point measured. Our data demonstrated increased elastasc concentrations during cardiopulmonary bypass, but we did not find enhanced intracoronaiy elastasc release or myocardial lipid peroxidation. Our data suggest that patients are sufficiently protectcd korn leucocyte mrdiatcd ischaemia reperfusion injuiy during uncomplicated coronary artery bypass grafting with cardioplrgic arrest.
Free Radical Biology and Medicine, 2000
Available evidence for oxidative stress after angioplasty is indirect or ambiguous. We sought to characterize the pattern, time course, and possible sources of free radical generation early after arterial balloon injury. Ex vivo injury performed in arterial rings in buffer with lucigenin yielded a massive oxygen-dependent peak of luminescence that decayed exponentially and was proportional to the degree of injury. Signals for injured vs. control arteries were 207.1 Ϯ 17.9 (n ϭ 13) vs 4.1 Ϯ 0.7 (n ϭ 22) cpm ϫ 10 3 /mg/min ( p Ͻ .001). Data obtained with 0.25 mmol/l lucigenin were validated with 0.005-0.05 mmol/l lucigenin or the novel superoxide-sensitive probe coelenterazine (5 mol/l). Gentle removal of endothelium prior to injury scarcely affected the amount of luminescence. Lucigenin signals were amplified 5-to 20-fold by exogenous NAD(P)H, and were Ͼ85% inhibited by diphenyliodonium (DPI, a flavoenzyme inhibitor). Antagonists of several other potential free radical sources, including xanthine oxidase, nitric oxide synthase, and mitochondrial electron transport, were without effect. Overdistension of intact rabbit iliac arteries in vivo (n ϭ 7) induced 72% fall in intracellular reduced glutathione and 68% increase in oxidized glutathione, so that GSH/GSSG ratio changed from 7.93 Ϯ 2.14 to 0.81 Ϯ 0.16 ( p Ͻ .005). There was also 28.7% loss of the glutathione pool. Further studies were performed with electron paramagnetic resonance spectroscopy. Rabbit aortas submitted to ex vivo overdistension in the presence of the spin trap DEPMPO (5-diethoxy-phosphoryl-5-methyl-1-pyrroline-N-oxide, 100 mmol/l, n ϭ 5) showed formation of radical adduct spectra, abolished by DPI or superoxide dismutase. Computer simulation indicated a mixture of hydroxyl and carbon-centered radical adducts, likely due to decay of superoxide adduct. Electrical mobility shift assays for NF-B activation were performed in nuclear protein extracts from intact or previously injured rabbit aortas. Balloon injury induced early NF-B activation, which was decreased by DPI. In conclusion, our data show unambiguously that arterial injury induces an immediate profound vascular oxidative stress. Such redox imbalance is likely accounted for by activation of vessel wall NAD(P)H oxidoreductase(s), generating radical species potentially involved in tissue repair.
International Journal of Rehabilitation Research, 2002
Blut und Lag phase von Low-density-Lipoprotein (LDL)). Zur Beurteilung der funktionalen Indizes des kardiorespiratorischen Systems wurde bei den Patienten vor Aufnahme in das Programm und nach Abschluss des Programms eine fahrradergometrische Untersuchung vorgenommen. Anhand des maximalen Sauerstoffverbrauchs (peak VO 2 ) 71 SD wurden drei Subgruppen mit unterschiedlicher aerober Kapazita¨t identifiziert: Z19ml/min pro kg (GR I, n¼7), 11-19 ml/min pro kg (GR II, n¼24) und r11ml/min pro kg (GR III, n¼5). Das Ausma des oxidativen Stresses war in allen Subgruppen deutlich erho¨ht. Die signifikanteste Verbesserung trat im Bereich der Lipidperoxidationsprodukte und der Lag phase von LDL auf. Die Indizes der kardiorespiratorischen Reserve und der ko¨rperlichen Leistungsfa¨higkeit ergaben hoch signifikante Anstiege, wa¨hrend die gu¨nstigsten Vera¨nderungen, wenn man sowohl die biochemischen als auch die chemischen Indizes beru¨cksichtigt, bei den Patienten mit der niedrigsten aeroben Kapazita¨t festgestellt wurden.