Search Results
Results 551 - 600 of 1214
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Chen Qun - - 2002
BACKGROUND: Brief sevoflurane exposure and washout (sevoflurane preconditioning [SPC]) before 30-min global ischemia at 37 degrees C is known to improve cardiac function, decrease cytosolic [Ca(2+)] loading, and reduce infarct size on reperfusion. It is not known if anesthetic preconditioning (APC) applies as well to hypothermic ischemia and reperfusion and ...
Ockaili Ramzi - - 2002
Sildenafil citrate (Viagra) is the pharmacological agent used to treat erectile dysfunction in men. Because this drug has a vasodilatory effect, we hypothesized that such an action may induce a preconditioning-like cardioprotective effect via opening of mitochondrial ATP-sensitive K (K(ATP)) channels. Rabbits were treated with sildenafil citrate (0.7 mg/kg iv) ...
Buehler Alexandra - - 2002
OBJECTIVE: This study was performed to evaluate the cardioprotective role of acidic fibroblast growth factor-1 (FGF-1) in transgenic mice with cardiac-specific overexpression of human FGF-1. METHODS: Mice were subjected to coronary artery occlusion for 15-75 min with a continuously recorded 3-lead electrocardiogram (ECG). Infarct size was measured and ERK-1 and ...
Piriou V - - 2002
BACKGROUND: Recent investigations showed that isoflurane can induce pharmacological preconditioning. The present study aimed to compare the potency of four different halogenated anaesthetics to induce preconditioning. METHODS: Anaesthetized open-chest rabbits underwent 30 min of coronary artery occlusion followed by 3 h of reperfusion. Before this, rabbits were randomized into one ...
Sakai Kenya - - 2002
Nicorandil has been reported to have a preconditioning effect which suppresses the ST-segment shift or lactate production during coronary angioplasty in patients with stable angina pectoris. The present study investigated whether the preconditioning effect of nicorandil affects troponin T (TnT) levels after coronary angioplasty. Twenty-four patients with stable angina pectoris ...
Tassani Peter - - 2002
The calcium sensitizer levosimendan (LEV) improves the function of stunned myocardium, cardiac performance in heart failure, and possibly the efficiency of myocardial work. The present experiments investigated the effect of LEV on myocardial contraction and metabolism of acutely ischaemic myocardium distal to a functionally effective coronary artery stenosis. Anaesthetised open ...
Beresewicz A - - 2002
Ceramide signalling has been implicated in the mechanism of myocardial ischemia/reperfusion injury (IR). This study tested the hypothesis that ceramides containing a specific amino-linked acyl residue mediate the injury, and that ischemic preconditioning (IPC) affords myocardial protection because it prevents increased ceramide accumulation in IR myocardium. Perfused rat hearts were ...
Krenz Maike - - 2002
In the rabbit heart, acute ethanol exposure followed by washout before ischemia exerts a preconditioninglike effect. However, if alcohol is still present during ischemia, all preconditioning-related cardioprotection is abolished. The present follow-up study investigated the dose-response relationships of both the beneficial and detrimental effects of acute ethanol exposure. In the ...
Lalu Manoj M - - 2002
Release and activation of matrix metalloproteinases (MMPs) significantly contribute to myocardial stunning injury immediately after ischemia and reperfusion, however, their role in preconditioning remains unknown. We therefore examined the effects of preconditioning and subsequent ischemia/reperfusion on MMP activity in isolated rat hearts. Hearts were subjected to a preconditioning protocol (three ...
Lellouche Nicolas - - 2002
In this study, pharmacological late preconditioning was induced in 53 rabbits with an adenosine A(1) receptor agonist (2-chloro-N(6)-cyclopentyladenosine, CCPA, 100 microg/kg), or a NO-donor (S-nitroso-N-acetyl-penicillamine, SNAP, 2.5 microg/kg/min; 75 min) vs. saline as control. Later, after 24 h, rabbits underwent a 30-min coronary occlusion and subsequent reperfusion. After 3 h ...
Wolfrum Sebastian - - 2002
OBJECTIVE: Myocardial protection can be achieved by brief ischemia-reperfusion of remote organs, a phenomenon described as remote preconditioning (RPC). Since the intracellular mechanisms of RPC are not known, we tested the hypothesis that RPC might activate myocardial PKCepsilon, an essential mediator of classical ischemic preconditioning. Furthermore, we tried to delineate ...
Joyeux Marie - - 2002
OBJECTIVE: We have investigated the involvement of the endocannabinoid system in the delayed cardioprotection conferred by heat stress preconditioning in the isolated rat heart. METHODS: Rats were divided into eight groups (n=7 in each group), subjected to either heat stress (42 degrees C for 15 min, HS groups) or sham ...
Weinbrenner Christof - - 2002
BACKGROUND: Ischemic preconditioning is a powerful mechanism in reducing infarct size of the heart. Protection can be performed either by an ischemic stimulus of the heart itself or by ischemia of an organ distant to the heart. To address the question whether this remote preconditioning is transduced by neuronal or ...
Smith Robert M - - 2002
OBJECTIVE: Tumor necrosis factor alpha (TNFalpha) is known to mimic ischemic preconditioning (IP). However, it is not known whether TNFalpha-preconditioning is mediated by 'established' preconditioning signaling or via novel signaling cascades. Moreover, whether TNFalpha is required to induce the ischemic preconditioning phenotype has not been determined. METHODS: To evaluate the ...
Dawn Buddhadeb - - 2002
Although Src protein tyrosine kinases (PTKs) have been shown to be essential in late preconditioning (PC) against myocardial stunning, their role in triggering versus mediating late PC against myocardial infarction remains unclear. Four groups of conscious rabbits were subjected to a 30-min coronary occlusion on day 2, with or without ...
Rajashree R - - 2002
The functional significance of ATP-sensitive K(+) (K(ATP)) channels is controversial. In the present study, transgenic mice expressing a mutant Kir6.2, with reduced ATP sensitivity, were used to examine the role of sarcolemmal K(ATP) in normal cardiac function and after an ischemic or metabolic challenge. We found left ventricular developed pressure ...
Legtenberg Roger J - - 2002
Glibenclamide preserves postischaemic myocardial function in the isolated, erythrocyte perfused, working rat heart model. This study addresses the possible involvement of KATP channels in this beneficial action of glibenclamide. We hypothesized that if glibenclamide improved postischaemic cardiac function by blocking of KATP channels, opening of these KATP channels should result ...
Saltman Adam E - - 2002
BACKGROUND: Many stimuli can successfully protect the heart against ischemia. We investigated whether gap junction uncoupling before ischemia was myoprotective. We also studied the function of the adenosine triphosphate-dependent potassium channel, which has been implicated in the mechanism of pharmacologic preconditioning, with respect to gap junction physiology. METHODS: Twenty-eight rabbit ...
Liu Xuwan - - 2002
The present study was designed to explore the protective effects of melatonin and its analogs, 6-hydroxymelatonin and 8-methoxy-2-propionamidotetralin, on the survival of doxorubicin-treated mice and on doxorubicin-induced cardiac dysfunction, ultrastructural alterations, and apoptosis in mouse hearts. Whereas 60% of the mice treated with doxorubicin (25 mg/kg ip) died in 5 ...
Gozal Y - - 2002
BACKGROUND AND OBJECTIVE: Myocardial ischaemic preconditioning is characterized by a reduction in the rate of glycolysis. Brief myocardial ischaemia also reduces the glycogen content of the heart. The first objective was to determine whether augmenting glucose oxidation by activation of the pyruvate dehydrogenase complex would prevent the infarct limitation of ...
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: ...
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