Search Results
Results 551 - 600 of 1194
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Tissier Renaud - - 2002
We investigated the influence of coronary artery reperfusion (CAR) duration on the infarct-limiting properties of adenosine A(1)-receptor stimulation-induced delayed preconditioning (A(1)-DPC) compared with ischemia-induced delayed preconditioning (I-DPC). Sixty-one chronically instrumented conscious rabbits successfully underwent the following protocol. On day 1, rabbits were randomly divided into four groups: control (saline, iv), ...
Schwartz Lisa M - - 2002
To test whether cardioprotection induced by ischemic preconditioning depends on the opening of mitochondrial ATP-sensitive K(+) (K(ATP)) channels, the effect of channel blockade was studied in barbital-anesthetized open-chest pigs subjected to 30 min of complete occlusion of the left anterior descending coronary artery and 3 h of reflow. Preconditioning was ...
Kodani Eitaro - - 2002
BACKGROUND: Although NO has been shown to serve both as the trigger and the mediator of the late phase of ischemic preconditioning (PC), it is unknown whether NO acts via activation of soluble guanylate cyclase (sGC). The objective of this study was to investigate the role of sGC in late ...
Baldwin Douglas - - 2002
BACKGROUND: We hypothesized that indices of myocyte contractility and metabolism could be preserved with ischemic preconditioning in a model of reversible ischemia similar to that occurring during routine cardiac surgery. Regional measures of metabolism and function have not been studied in conjunction with individual myocyte function during postischemic recovery of ...
Sigg Daniel C - - 2002
Opioids are involved in cardiac ischemic preconditioning. Important species differences in cellular signaling mechanisms, antiarrhythmic, and antistunning effects have been described. The role of the delta-opioid receptor activation in swine remains unknown. Forty minutes before a 45-min occlusion and 180-min reperfusion of the left anterior descending coronary artery, open-chest, pentobarbital-anesthetized ...
Tokuno Shinichi - - 2002
To investigate if spontaneous ischemic events in mice with severe multi-organ atherosclerosis could adapt to ischemia, apolipoprotein E/LDL receptor knockout mice were fed an atherogenic diet for 7 to 9 months. Signs of spontaneous ischemia occurred. One to two days later, hearts were excised, Langendorff-perfused with induced global ischemia, and ...
Napoli Claudio - - 2002
Protease-activated receptor-2 (PAR-2) is a member of seven transmembrane domain G protein-coupled receptors activated by proteolytic cleavage. PAR-2 is involved in inflammatory events and cardiac ischemic reperfusion injury. The objective of this study was to investigate the effects of PAR-2 in experimental myocardial ischemic preconditioning. To monitor the effects of ...
Wu Z K ZK Division of Cardiac Surgery, Tampere University Hospital, Tampere, - - 2002
To test whether ischemic preconditioning (IP) is able to protect the myocardium in recently unstable CABG patients. prospective, randomised, controlled clinical study. University Hospital. Forty CABG patients with recent unstable angina were randomised into an IP group (n=20) and a control group (n=20). Subgroup was divided based on the time ...
Vogt Achim M - - 2002
Exact adjustment of the Embden-Meyerhof pathway (EMP) is an important issue in ischemic preconditioning (IP) because an attenuated ischemic lactate accumulation contributes to myocardial protection. However, precise mechanisms of glycolytic flux and its regulation in IP remain to be elucidated. In open chest pigs, IP was achieved by two cycles ...
Berenshtein Eduard - - 2002
Iron and copper play major roles in biological systems, catalyzing free radical production and consequently causing damage. The relatively high levels of these metals, which are mobilized into the coronary flow following prolonged ischemia, have been incriminated as key players in reperfusion injury to the heart. In the present communication ...
Spear Joseph F - - 2002
The effects of 20-min ligations of the anterior branch of the left coronary artery were studied in Langendorff-perfused rabbit hearts with 92 microM D-sotalol added to the perfusate to induce long QT intervals and triggered arrhythmias. Epicardial electrograms, a left ventricular endocardial monophasic action potential, and simulated X and Y ...
Akula A - - 2002
The cardioprotective involvement of bradykinin was evaluated using the ACE inhibitor, lisinopril, and the APP inhibitor, 2-mercaptoethanol alone and in combination in rats with experimental myocardial infarction. The signal cascade mechanism mediating the cardioprotective actions of bradykinin was evaluated by administering aspirin and methylene blue prior to lisinopril and 2-mercaptoethanol ...
Li Guohu - - 2002
BACKGROUND: Emerging evidence suggests that gap junction-mediated intercellular transmission of ions, metabolites and/or second messengers may serve as important determinants of myocyte viability. Our aim was to determine, using isolated buffer-perfused mouse hearts, whether the cardioprotection achieved with ischemic preconditioning (PC) is due in part to: (i) disruption of cell-cell ...
Rock Peter - - 2002
The purpose of this review is to describe in more detail ischemia reperfusion injury and preconditioning, and to speculate on the potential role of preconditioning in the care of critically ill patients. Current hemodynamic treatment of hypotension and hypoperfusion in critically ill patients is directed at ensuring essential organ perfusion ...
Vanden Hoek Terry L - - 2002
A major challenge in improving cardiac arrest survival is organ injury that occurs after the return of spontaneous circulation. This postresuscitation injury may result in as many as 90% of such patients not surviving to hospital discharge. Preconditioning, an adaptive physiologic response found in multiple organs and species, may help ...
Agnew N M - - 2002
Early studies indicated that isoflurane caused coronary steal and should therefore be avoided in patients with coronary heart disease. Subsequently, more detailed trials have disputed this and have shown that as long as coronary perfusion pressure is maintained, isoflurane does not cause coronary steal or myocardial ischaemia. There is now ...
Pagel Paul S - - 2002
Chronic consumption of small doses of ethanol protects myocardium from ischemic injury. We tested the hypothesis that mitochondrial and sarcolemmal adenosine triphosphate-dependent potassium (K(ATP)) channels mediate these beneficial effects. Dogs (n = 76) were fed with ethanol (1.5 g/kg) or water mixed with dry food bid for 6 or 12 ...
Vogt Achim M - - 2002
In ischemia, the myocardial metabolic status determines the expansion of necrosis. Decreased ATP levels and increased lactate contents in ischemic myocardium undergoing lethal injury are known to be related to the expansion of irreversible damage. However, their individual contributions have not yet been firmly established. Using two differently effective protocols ...
Lee Tsung Ming - - 2002
OBJECTIVES: The purpose of this study was to determine whether administration of estrogen produces cardioprotective effects in patients undergoing coronary angioplasty. BACKGROUND: We have previously demonstrated that estrogen can provide cardioprotection by activating the mitochondrial adenosine triphosphate-sensitive potassium (K(ATP)) channel, a major contributor to ischemic cardioprotection. METHODS: Fifty patients undergoing ...
Kehl Franz - - 2002
BACKGROUND: Volatile anesthetics precondition against myocardial infarction, but it is unknown whether this beneficial action is threshold- or dose-dependent. The authors tested the hypothesis that isoflurane decreases myocardial infarct size in a dose-dependent fashion in vivo. METHODS: Barbiturate-anesthetized dogs (n = 40) were instrumented for measurement of systemic hemodynamics including ...
Sasaki Hiroaki - - 2002
A modern experimental strategy for treating myocardial ischemia is to induce neovascularization of the heart by the use of "angiogens", mediators that induce the formation of blood vessels, or angiogenesis. Studies demonstrated that coronary collateral vessels protect ischemic myocardium after coronary obstruction; therefore we sought to examine a novel method ...
Neckár Jan - - 2002
The objective of the work was to examine whether adaptation to intermittent high altitude hypoxia and ischaemic preconditioning provide additive protection of the heart against subsequent acute ischaemic injury. Adult male rats were exposed to hypoxia (7000 m, 8 h/day, 24-30 exposures) in a hypobaric chamber. Susceptibility of their hearts ...
Williams Scott D - - 2002
Calcium-independent phospholipase A(2) (iPLA(2)) is the predominant phospholipase A(2) present in myocardium, and its pathophysiological role in acute myocardial infarction has been suggested by the rapid increase in membrane-associated iPLA(2) activity during myocardial ischaemia and reperfusion (I/R). We therefore examined iPLA(2) in mitochondrial fractions prepared from Langendorff-perfused adult rabbit hearts. ...
Bell Robert M - - 2002
BACKGROUND: Nitric oxide (NO), synthesised from the inducible isoform of nitric oxide synthase (iNOS), is implicated in mediating second window of protection (SWOP)/delayed ischemic preconditioning. However the role of NO and iNOS in delayed pharmacological protection remains unclear and is the subject of this investigation. METHODS: To test the hypothesis ...
Suzuki Masashi - - 2002
Recently it has been postulated that mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channels rather than sarcolemmal K(ATP) (sarcK(ATP)) channels are important as end effectors and/or triggers of ischemic preconditioning (IPC). To define the pathophysiological significance of sarcK(ATP) channels, we conducted functional experiments using Kir6.2-deficient (KO) mice. Metabolic inhibition with glucose-free, dinitrophenol-containing solution ...
Sommerschild Hilchen T - - 2002
The term 'preconditioning' refers to the paradoxical phenomenon that pretreatment with a potential noxious stress-stimulus can increase cellular tolerance to subsequent noxious stress-stimuli. This was first described in an experimental model in dogs in which short-lasting periods of myocardial ischemia resulted in reduced infarction during a subsequent long-lasting coronary artery ...
Kawada Toru - - 2002
Although brief ischaemic events make the myocardium tolerant to subsequent prolonged ischaemia, known as ischaemic preconditioning, whether brief ischaemia also affects neural regulation at the in vivo heart remains unknown. We examined the effects of brief ischaemia on myocardial interstitial acetylcholine (ACh) and noradrenaline (NA) levels in anaesthetized cats (n ...
Nakano Atsushi - - 2002
A previous study in dogs indicated that preconditioning (PC) of a specific myocardial region not only evoked a local cardioprotective effect but also rendered remote myocardium resistant to infarction. In the present study we devised a method to test for remote PC in the rabbit which it is not possible ...
Iliodromitis Efstathios K - - 2002
BACKGROUND: Angiotensin II (Ang) has been successfully used as a preconditioning analogue in isolated rabbit hearts. It is also known that local concentrations of Ang accelerate ischemic injury in vivo, while activation of stretch receptors protects ischemic hearts. OBJECTIVES: First, to investigate further whether Ang can mimic preconditioning in vivo. ...
Tanoue Yoshihisa - - 2002
OBJECTIVES: Ischemic preconditioning has been used to induce the myocardium to adapt to ischemic stress preceded by short periods of ischemia and reperfusion. We used a sheep right heart bypass model with a conductance catheter to assess the cardioprotective effect of ischemic preconditioning on 30-minute normothermic global myocardial ischemia. METHODS: ...
Teoh L K K - - 2002
OBJECTIVES: Ischemic preconditioning is known to protect the human heart from ischemic injury during coronary artery bypass graft (CABG) surgery but is not practised routinely. Adenosine A1 receptor agonists may confer protection in this setting by mimicking preconditioning. The aim of this study was to compare preconditioning, by ischemia or ...
Babai László - - 2002
1. Dogs, anaesthetized with chloralose and urethane, were subjected to a 25 min occlusion of the left anterior descending coronary artery. This resulted in ventricular ectopic activity, a reduction in baroreflex sensitivity (BRS, measured following the intravenous administration of phenylephrine), elevations in the epicardial ST-segment and increases in the degree ...
Kloner R A - - 2001
In experimental studies in the dog, total proximal coronary artery occlusions of up to 15 minutes result in reversible injury, meaning that the myocytes survive this insult. The 15 minutes of ischemia, however, induce numerous changes in the myocardium, including certain monuments to the brief episode of ischemia that may ...
Kloner R A - - 2001
In experimental studies in the dog, total proximal coronary artery occlusions of up to 15 minutes result in reversible injury, meaning that the myocytes survive this insult. The 15 minutes of ischemia, however, induce numerous changes in the myocardium, including certain monuments to the brief episode of ischemia that may ...
Zhou Z H - - 2001
Improvement of preservation with cardioplegic solution by nitroglycerin-induced delayed preconditioning was studied in the isolated rat heart. The isolated rat heart was arrested using St. Thomas Hospital solution, and then reperfused with normothermic Krebs-Henseleit solution for 40 min after a 4-h hypothermic ischemic period. Heart rate, coronary flow, left ventricular ...
Tissier R - - 2001
1. The goal of this study was to investigate the effects of the delayed pharmacological preconditioning produced by an adenosine A(1)-receptor agonist (A(1)-DPC) against ventricular arrhythmias induced by ischaemia and reperfusion, compared to those of ischaemia-induced delayed preconditioning (I-DPC). 2. Eighty-nine instrumented conscious rabbits underwent a 2 consecutive days protocol. ...
Lee T M - - 2001
Pravastatin has been shown, in an experimental model of ischemia reperfusion, to increase adenosine levels, which exert a potent and protective effect on the heart. The purpose of this study was to investigate whether pravastatin can provide cardioprotection by increased production of adenosine in patients undergoing coronary angioplasty, a clinical ...
Hale S L - - 2001
The aim of this study was to test whether myocardial infarct size reduction would be optimized by combining three known effective therapies: cariporide, regional hypothermia, and ischemic preconditioning (CHIP). Before coronary artery occlusion (CAO), treated rabbits (CHIP, n = 7) received cariporide (0.3 mg/kg), ischemic preconditioning (7 minutes ischemia and ...
Bell R M - - 2001
Nitric oxide (NO) is implicated in triggering and mediating delayed preconditioning. However, the role of NO and endothelial nitric oxide synthase (eNOS) in early ischaemic preconditioning is controversial. To investigate the role of eNOS in this paradigm further, the response of hearts isolated from either eNOS knockout (KO) or eNOS ...
Wu Z K - - 2001
OBJECTIVE: We sought to investigate the effects of myocardial ischemic preconditioning in adult and aged patients undergoing coronary artery bypass grafting. METHODS: Eighty patients with 3-vessel disease undergoing coronary artery bypass grafting were randomized into one of the following groups: adult ischemic preconditioning, adult control, aged ischemic preconditioning, and aged ...
Rochetaing A - - 2001
This study was designed to investigate whether exposure to carbon monoxide (CO) could alter or raise the ischemic tolerance induced by preconditioning. To this end, isolated rat hearts were aerobically perfused for 20 min. Hearts were then randomized to two groups: (1) a further 20-min aerobic perfusion, and (2) ischemic ...
Bolli R R Division of Cardiology, University of Louisville and the Jewish Hospital Heart and Lung Institute, Louisville, KY 40292, - - 2001
Over the past decade, an enormous number of studies (>100) have focused on the role of nitric oxide (NO) in myocardial ischemia. It is important to distinguish the function of NO in unstressed (non-preconditioned) myocardium from its function in preconditioned myocardium (i.e. myocardium that has shifted to a defensive phenotype ...
Schulman D - - 2001
Ischemic preconditioning (IP) reduces infarct size in young animals; however, its impact on aging is underinvestigated. The effect of variations in IP stimuli was studied in young, middle-aged, and aged rat hearts. Isolated hearts underwent 35 min of regional ischemia and 120 min of reperfusion. Hearts with IP were subjected ...
Müllenheim J - - 2001
PURPOSE: Ischemic preconditioning protects the heart against subsequent prolonged ischemia by opening of adenosine triphosphate-sensitive potassium (K(ATP)) channels. Thiopentone blocks K(ATP) channels in isolated cells. Therefore, we investigated the effects of thiopentone on ischemic preconditioning. METHODS: Isolated rat hearts (n=56) were subjected to 30 min of global no-flow ischemia, followed ...
Xi L - - 2001
Whole body hyperthermia (WBH) is a distinctive pathophysiological condition with significant impact on tissue metabolism and organ functions. WBH has been investigated as a promising adjunct therapy to the conventional chemo- or radiotherapy for treating certain types of cancer. Numerous studies have shown that WBH is associated with induction of ...
Schaefer S - - 2001
BACKGROUND: Ischemic preconditioning is characterized by the limitation of infarct size or ischemic signs after one or more brief episodes of ischemia, a process that probably involves stimulation of adenosine receptors. One human model of ischemic preconditioning is repetitive occlusion of a coronary artery during angioplasty. By using this method ...
Ebrahim Z - - 2001
Bradykinin is an important endogenous mediator exerting acute protective effects in the ischemic myocardium. The aims of this study were to investigate whether exogenously administered bradykinin could evoke delayed myocardial protection and to determine whether any protection observed might be dependent on nitric oxide (NO) generation. Conscious rats received bradykinin ...
Di Pede F - - 2001
BACKGROUND: Spinal cord stimulation (SCS) has analgesic properties and may be used to treat pain in patients with therapeutically refractory angina who are unsuitable for myocardial revascularization. Some studies have also demonstrated an anti-ischemic effect. The aim of this study was to evaluate the long-term persistence of the effects of ...
Schwartz L M - - 2001
These studies were undertaken to determine the duration of protection against myocardial infarction provided by ischemic preconditioning in the canine heart, and to learn if cardioprotection can be restored by another preconditioning stimulus when the initial effect is lost. Control and four preconditioning groups of anesthetized, open-chest dogs were compared. ...
Hill M - - 2001
BACKGROUND: Recent studies suggest that the late phase of ischemic preconditioning (PC) can be mimicked by pretreatment with NO donors. The ability of clinically relevant NO donors to induce PC against infarction, however, has not been evaluated. Furthermore, it is unknown whether tolerance to the hemodynamic actions of nitrates also ...
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