Search Results
Results 651 - 700 of 1190
< 9 10 11 12 13 14 15 16 17 18 19 >
Feng J - - 2000
BACKGROUND: Depressed myocardial performance is an important clinical problem after open heart surgery. We hypothesized pretreating with bradykinin would pharmacologically precondition the heart and improve post-ischemic performance, and induce myocardial preconditioning by activating nitric oxide synthase. METHODS: Thirty-three rabbit hearts underwent retrograde perfusion with Krebs-Henseleit buffer (KHB) followed by 50 ...
Napoli C - - 2000
The term "ischemic preconditioning (PC)" was first applied to canine myocardium subjected to brief episodes of ischemia and reperfusion that tolerated a more prolonged episode of ischemia better than myocardium not previously exposed to ischemia. Protective effect of myocardial ischemic PC was demonstrated in several animal species, resulting in the ...
Guo Y - - 2000
Recent studies have demonstrated that cyclooxygenase-2 (COX-2) is an essential mediator of the cardioprotective effects of the late phase of ischemic preconditioning (PC) in rabbits. The goal of this study was to determine whether COX-2 also plays an essential role in late PC in the mouse. B6129F2/J mice underwent a ...
Xi L - - 2000
The phenomenon of 'ischemic preconditioning' (IP) has been vigorously investigated during the past 15 years. As our knowledge on the possible protective mechanisms of IP has been increasingly expanded, novel approaches based on preconditioning with pharmacological agents have recently emerged. Two drugs have been used to induce delayed preconditioning against ...
Sato M - - 2000
BACKGROUND: Ischemic preconditioning (PC) represents a state-of-the-art technique for myocardial preservation. Although certain intracellular mediators have been shown to play a role in PC, the exact nature of the trigger for PC is not known. Our previous study demonstrated that intracellular bradykinin released from the heart during ischemia/reperfusion plays a ...
Toyoda Y - - 2000
Adenosine-enhanced ischemic preconditioning (APC) extends the protection afforded by ischemic preconditioning (IPC) by both significantly decreasing infarct size and significantly enhancing post-ischemic functional recovery. In this study, the anti-infarct effects and the anti-stunning effects of APC in contributing to enhanced post-ischemic functional recovery were determined and compared with IPC. Sheep ...
Matsuyama N - - 2000
BACKGROUND: Ischemic preconditioning (IPC) and pharmacological preconditioning (PPC) have both been shown to confer cardioprotective effects. However, the role of protein synthesis in preconditioning is unclear. METHODS AND RESULTS: Isolated rabbit hearts were treated with cycloheximide (CHx, 10 micromol/L), a protein synthesis inhibitor at the translational level, before 2 cycles ...
Wu Z K - - 2000
BACKGROUND: Preservation of right ventricular myocardium is unsatisfactory in patients with critical stenosis or occlusion of the right coronary artery. The aim of this study was to investigate whether ischemic preconditioning (IP) improved the recovery of right ventricular function after coronary artery bypass grafting. METHODS: Forty patients with three-vessel disease ...
Matsumura K - - 2000
Protein kinase C (PKC) has been known to play an important role in ischemic preconditioning (IP). This study was designed to examine whether the translocation of PKC is associated with the cardioprotective effects of IP in vivo on infarct size and ventricular arrhythmias in a rat model. Using anesthetized rats, ...
Futterman L G - - 2000
Hibernation is a chronic condition that can be due to either chronic low perfusion or repetitive stunning. When oxygen demands increase, prolonged periods of ischemia occur, resulting in multiple episodes of stunning. Because hibernation may play a significant role in refractory failure, the diagnosis of hibernation followed by reperfusion can ...
Takano H - - 2000
The role of ATP-sensitive potassium (K(ATP)) channels in the late phase of ischemic preconditioning (PC) remains unclear. Furthermore, it is unknown whether K(ATP) channels serve as end effectors both for late PC against infarction and against stunning. Thus, in phase I of this study, conscious rabbits underwent a 30-min coronary ...
Takano H - - 2000
It is unknown whether late preconditioning (PC) enhances the recovery of left ventricular (LV) function after a myocardial infarction. Thus 25 conscious rabbits were subjected to a 30-min coronary occlusion followed by 28 days of reperfusion after PC 24 h earlier with either ischemia or nitric oxide donor administration [S-nitroso-N-acetylpenicillamine ...
Falck G - - 2000
PURPOSE: Despite detailed knowledge of the effects of X-ray contrast media on cardiac function, no studies have examined the effect of contrast media injections on the subsequent tolerance to ischemia in the heart. METHODS: Isolated perfused rat hearts were exposed to repetitive injections of iohexol, iodixanol, or ioxaglate before 30 ...
Feng J - - 2000
The objective of this study was to investigate if a variation in extracellular-K+ concentrations alters the effects of global pre-conditioning on ischemia-induced arrhythmias. Rat hearts were Langendorff-perfused with Krebs-Henseleit solution and randomised in 8 groups (n = 12/group): four control groups (K+: 2, 4, 6, or 8 mmol/L) which underwent ...
Sharma A - - 2000
The present study is designed to investigate the role of Na+ -H+ exchanger in the cardioprotective effect of ischaemic and angiotensin (Ang II) preconditioning. Isolated perfused rat heart was subjected to global ischaemia for 30 min followed by reperfusion for 120 min. Coronary effluent was analysed for LDH and CK ...
Sharma A - - 2000
The present study is designed to investigate the mechanism of cardioprotective effect of angiotensin II preconditioning. Isolated perfused rat heart was subjected to global ischaemia for 30 min followed by reperfusion for 120 min. Coronary effluent was analysed for lactate dehydrogenase and creatine kinase enzyme release to assess the degree ...
Singh D - - 2000
The present study was designed to investigate the effect of actinomycin D, a transcription inhibitor, and cycloheximide, a translation inhibitor, on the delayed cardioprotective effect of ischemic preconditioning. Left thoracotomy was performed in anaesthetized rats at 4th/5th intercostal space and polypropylene suture (5-0) was employed to occlude left common coronary ...
Tang W - - 2000
Postresuscitation myocardial dysfunction has been recognized as a leading cause of the high postresuscitation mortality rate. We investigated the effects of ischemic preconditioning and activation of ATP-sensitive K(+) (K(ATP)) channels on postresuscitation myocardial function. Ventricular fibrillation (VF) was induced in 25 Sprague-Dawley rats. Cardiopulmonary resuscitation (CPR), including mechanical ventilation and ...
Tracey W R - - 2000
This study investigated whether aldose reductase (AR) inhibition with zopolrestat, either alone or in combination with an adenosine A(3)-receptor agonist (CB-MECA), reduced myocardial ischemic injury in rabbit hearts subjected to 30 min of regional ischemia and 120 min of reperfusion. Zopolrestat reduced infarct size by up to 61%, both in ...
Toufektsian M C - - 2000
Oxygen radical scavengers have been shown to prevent the development of ischemic preconditioning, suggesting that reactive oxygen species (ROS) might be involved in this phenomenon. In the present study, we have investigated whether direct exposure to ROS produced by photoactivated Rose Bengal (RB) could mimic the protective effects of ischemic ...
Yellon D M - - 2000
The possibility that an innate mechanism of myocardial protection might be inducible in the human heart has generated considerable excitement and enthusiastic research. The potential to enhance myocardial resistance to ischemic injury in patients suffering the consequences of coronary artery disease has led to studies with more direct clinical relevance. ...
Oliveira P J - - 2000
Carvedilol (¿1-[carbazolyl-(4)-oxy]-3-[2-methoxyphenoxyethyl)amino]-pro panol-(2) ¿) is a novel compound used in clinical practice for the treatment of congestive heart failure, mild to moderate hypertension, and myocardial infarction. Carvedilol was also shown to protect cardiac mitochondria from oxidative stress events. Because mitochondria are the main suppliers of ATP for cardiac muscle work, ...
Ahmet I - - 2000
BACKGROUND: We have reported a similar cardioprotective effect and mechanism of diadenosine tetraphosphate (AP4A) and ischemic preconditioning in rat hearts. In this study, the applicability of AP4A administration to cardiac surgery was tested by using a canine cardiopulmonary bypass model. METHODS: Hearts underwent 60 minutes of cardioplegic arrest (34 degrees ...
Yoshida T - - 2000
BACKGROUND: Ischemic preconditioning has been proven to be a powerful tool for myocardial protection in the setting of ischemia and reperfusion. A new drug to provide pharmacologic preconditioning, monophosphoryl lipid A (MLA), was administered 24 hours before an acute coronary occlusion in pigs to determine the effect on pharmacologic preconditioning. ...
Li F - - 2000
BACKGROUND: The Langendorff model was used to determine whether pretreatment with sevoflurane, isoflurane, or ischemic preconditioning (IP) could protect the myocardium of rats against global ischemia. METHODS: After 15-min perfusion, each isolated heart was assigned to (1) Control group: no pretreatment, (2) Sevoflurane group: 20-min exposure of 1.7% sevoflurane prior ...
Morrison R R - - 2000
The role of A(1) adenosine receptors (A(1)AR) in ischemic preconditioning was investigated in isolated crystalloid-perfused wild-type and transgenic mouse hearts with increased A(1)AR. The effect of preconditioning on postischemic myocardial function, lactate dehydrogenase (LDH) release, and infarct size was examined. Functional recovery was greater in transgenic versus wild-type hearts (44.8 ...
Tanhehco E J - - 2000
This investigation examined the effect of preconditioning in an in vivo model of ischemia-reperfusion injury. Anesthetized New Zealand White rabbits underwent 30 min of regional myocardial ischemia followed by 2 h of reperfusion. Hearts preconditioned with two cycles of 5 min ischemia-10 min reperfusion (IPC) or with the ATP-sensitive K ...
Piriou V - - 2000
BACKGROUND: Both mitochondrial adenosine triphosphate-sensitive potassium (MKATP) channels (selectively blocked by 5-hydroxydecanoate) and stretch-activated channels (blocked by gadolinium) have been involved in the mechanism of ischemic preconditioning. Isoflurane can reproduce the protection afforded by ischemic preconditioning. We sought to determine whether isoflurane-induced preconditioning may involve MKATP and stretch-activated channels. METHODS: ...
Shinmura K - - 2000
We examined the role of cyclooxygenase-2 (COX-2) in the late phase of ischemic preconditioning (PC). A total of 176 conscious rabbits were used. Ischemic PC (six cycles of 4-min coronary occlusions/4-min reperfusions) resulted in a rapid increase in myocardial COX-2 mRNA levels (+231 +/- 64% at 1 h; RNase protection ...
Coetzee W A - - 2000
The action of pharmacological openers of K(ATP) channels depends on the availability and levels of various intracellular nucleotides. Since these are subject to change during myocardial ischaemia, K(ATP) channel openers may affect ischaemic and non-ischaemic tissue differentially. Using a recently developed dual coronary perfusion method, we investigated the effects on ...
Cohen M V - - 2000
BACKGROUND: In a previous study, we found that recovery of segment shortening in the ischemic zone of conscious, chronically instrumented rabbits was significantly better in ischemically preconditioned than control animals after 72 hours of reperfusion. However, although this period of reperfusion was felt to be sufficient to allow recovery from ...
Saltman A E - - 2000
BACKGROUND: Ischemic preconditioning (IPC) decreases infarct size after global or regional ischemia. Potassium channel openers also precondition but are subject to dose-limiting vasodilation. We compared the mechanical and electrophysiological effects of ischemic and pharmacological preconditioning in an isolated rabbit heart model. METHODS: Rabbit hearts were preconditioned with either 10 micromol/L ...
Gaudette G R - - 2000
BACKGROUND: Both potassium channel openers and protein kinase C have been shown to independently elicit the myoprotective preconditioning response. However, the in vivo dependency between the two is unknown. METHODS: Thirty-seven sheep were divided into seven groups; animals received no pretreatment, pinacidil, pinacidil and potassium channel opener blocker glibenclamide, protein ...
Belhomme D - - 2000
BACKGROUND: The large number of experimental studies showing that adenosine "turns on" the protein kinase C (PKC)-mediated pathway that accounts for the cardioprotection conferred by ischemic preconditioning contrasts with the scarcity of clinical data documenting the preconditioning-like protective effect of adenosine during cardiac operations on humans. METHODS: Forty-five patients undergoing ...
Laude K - - 2000
Preconditioning the heart with brief periods of ischaemia induces delayed endothelial protection against reperfusion injury, but the precise mechanisms involved in this endogenous protein are still unclear. Induction of the type II-nitric oxide synthase (iNOS) acts as a mediator of the preconditioning against myocardial infarction and stunning. The present study ...
Clavien P A - - 2000
To determine whether ischemic preconditioning protects the human liver against a subsequent period of ischemia in patients undergoing hemihepatectomy, and to identify possible underlying protective mechanisms of ischemic preconditioning, such as inhibition of hepatocellular apoptosis. Ischemic preconditioning is a short period of ischemia followed by a brief period of reperfusion ...
Miki T - - 2000
BACKGROUND: Activation of protein kinase C-linked receptors and subsequent opening of the mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channel are crucial in preconditioning (PC). This study examined whether postinfarct ventricular remodeling interferes with the PC mechanism. METHODS AND RESULTS: Two weeks before isolation of hearts, rabbits underwent a sham operation or coronary ...
Nakano A - - 2000
Nitric oxide (NO) has been reported to play an important role in the late phase of ischemic preconditioning (PC) in the rabbit heart. However, the role of NO in the early phase of ischemic PC ("classical PC") is controversial. Accordingly, the present study was designed to determine whether NO contributes ...
Stvolinsky S L - - 2000
This review summarizes the data on anti-ischemic activity of carnosine. The pronounced anti-ischemic effects of carnosine in the brain and heart are due to the combination of antioxidant and membrane-protecting activity, proton buffering capacity, formation of complexes with transition metals, and regulation of macrophage function. In experimental cerebral ischemia, carnosine ...
Minners J - - 2000
BACKGROUND: Recent studies have postulated that mitochondrial ATP-sensitive potassium (mitoK(ATP)) channel activation may modulate mitochondrial function with the resultant induction of a preconditioning phenotype in the heart. We hypothesized that the modulation of mitochondrial homeostasis might confer preconditioning-like cardioprotection. METHODS: We used a model of regional ischemia in Langendorff-perfused isolated ...
Lee T M - - 2000
We have previously demonstrated the effects of estrogen on modulation of myocardial ATP-sensitive K(+)(K(ATP)) channel. Previous studies have demonstrated that activation of mitochondrial K(ATP)channel is a major contributor of ischemic cardioprotection. The purpose of the present study was to investigate the role of K(ATP)channel in estrogen-induced myocardial protection after ischemia/reperfusion ...
Pan H L - - 2000
Ischemic preconditioning is known to protect the myocardium from ischemia-reperfusion injury. We examined the transmural release of bradykinin during myocardial ischemia and the influence of ischemic preconditioning on bradykinin release during subsequent myocardial ischemia. Myocardial ischemia was induced by occlusion of the left anterior descending coronary artery in anesthetized cats. ...
Sharma A - - 2000
The present study is designed to investigate the mechanism of the cardioprotective effect of ischaemic preconditioning. Isolated perfused rat heart was subjected to global ischaemia for 30 min followed by reperfusion for 120 min. Coronary effluent was analysed for LDH and CK release to assess the degree of cardiac injury. ...
Yabe K - - 2000
OBJECTIVE: A possible link between activation of PKC and improvement of energy metabolism during reperfusion in ischemic preconditioning hearts was examined. METHODS: Isolated perfused rat hearts were preconditioned by 5-min ischemia and 5-min reperfusion in the presence and absence of a PKC inhibitor polymyxin B (50 microM) and then subjected ...
Rubino A - - 2000
Exposing the heart to brief episodes of ischaemia protects the myocardium and vascular endothelial cells against functional damage and cell death caused by subsequent prolonged ischaemia. Elucidation of the mechanisms that are involved in this phenomenon known as 'ischaemic preconditioning' and identification of drugs that mimic the protective response have ...
Toller W G - - 2000
BACKGROUND: Volatile anesthetic-induced preconditioning is mediated by adenosine triphosphate-dependent potassium (KATP) channels; however, the subcellular location of these channels is unknown. The authors tested the hypothesis that desflurane reduces experimental myocardial infarct size by activation of specific sarcolemmal and mitochondrial KATP channels. METHODS: Barbiturate-anesthetized dogs (n = 88) were acutely ...
Kawasuji M - - 2000
BACKGROUND: Ischemic preconditioning has been advocated as a method of cardioprotection for minimally invasive direct coronary artery bypass. This study was performed to estimate the cardioprotective effect of ischemic preconditioning before ischemia by examining the changes in myocardial tissue oxygenation and also to examine whether adenosine triphosphate-sensitive potassium channel opener ...
Kirsch M - - 2000
BACKGROUND: Myocardial preconditioning with brief coronary artery occlusions before a sustained ischemic period is reported to reduce infarct size. We wished to evaluate whether ischemic preconditioning (IP) is efficient in an experimental brain death (BD) model in the rabbit. METHODS: Rabbits were randomized into four experimental groups of eight animals ...
Pomerantz B J - - 2000
INTRODUCTION: Consistently, clinical series record supraventricular tachyarrhythmias in approximately 30% of patients following coronary artery bypass surgery (CABG). Ischemic preconditioning and adenosine preconditioning (Ado-PC) decrease postischemia/reperfusion (I/R) myocardial stunning, infarct size, and pharmacologically induced arrhythmias in all species including man. We hypothesized that adenosine preconditioning would decrease spontaneous pre- and ...
Post H - - 2000
Endogenous nitric oxide (NO) is involved in the protection by classical ischemic preconditioning (IP) against ischemia-induced arrhythmias in anesthetized dogs. Furthermore, NO triggers and mediates protection against infarction and stunning in delayed IP in conscious rabbits. Up to now it is unclear whether or not endogenous NO is also involved ...
< 9 10 11 12 13 14 15 16 17 18 19 >