We hypothesized that calpain inhibitor-1 protected left ventricular (LV) function from ischemia-reperfusion injury by inhibiting the proteolysis of alpha-fodrin. To test this hypothesis, we investigated the effect of calpain inhibitor-1 on LV mechanical work and energetics in the cross-circulated rat hearts that underwent 15-min global ischemia and 60-min reperfusion (n ...

We investigated the role of endothelin-A (ETA) and endothelin-B (ETB) receptors in ischemia/reperfusion-induced cardiac dysfunction and norepinephrine overflow using isolated rat hearts. According to the Langendorff technique, isolated hearts were subjected to 40 minutes of global ischemia followed by 30 minutes of reperfusion. Ischemia/reperfusion led to decreases in left ventricular ...

We have proposed that pharmacological preconditioning, leading to PKC-epsilon activation, in hearts improves postischemic functional recovery through a decrease in actomyosin ATPase activity and subsequent ATP conservation. The purpose of the present study was to determine whether moderate PKC-independent decreases in actomyosin ATPase are sufficient to improve myocardial postischemic function. ...

Heat shock (HS) pretreatment of the heart is effective in mitigating the deleterious effects of ischaemia/reperfusion. The main objective of this study was to determine whether the beneficial effect of HS is associated with the preservation of intracellular Ca2+ handling in the ischaemic/reperfused, isolated rat heart. Twenty-four hours after raising ...

The aim of this study was to investigate whether and how protein kinase C (PKC) was involved in the protection afforded by intermittent hypoxia (IH) and the subcellular distribution of different PKC isozymes in rat left ventricle. Post-ischemic recovery of left ventricular developed pressure and +/-dP/dtmax in IH hearts were ...

AIM: Na/Ca-exchanger (NCX) and sarcoplasmic reticulum (SR) roles during the protection by a cardioplegic solution (25 mm K and 0.5 mm Ca, CPG) against ischaemia-reperfusion was studied. METHODS: Contractile performance (CP) and high energy phosphates contents (HEP) were evaluated in isolated ventricles from rats. They were pre-treated with Krebs (C) ...

We investigated the contribution of dexamethasone treatment on the recovery of postischemic cardiac function and the development of reperfusion-induced arrhythmias in ischemic/reperfused isolated rat hearts. Rats were treated with 2 mg/kg of intraperitoneal injection of dexamethasone, and 24 hours later, hearts were isolated according to the 'working' mode, perfused, and ...

Strangulation is associated with an increased risk of mortality and morbidity in patients with mechanical bowel obstruction. The accurate and early recognition of the presence of strangulation is important to allow safe nonoperative treatment. A number of studies have shown that there was no single and reliable test to detect ...

Isoflurane enhances myocardial functional recovery and improves energy levels after ischemia. We sought to determine whether isoflurane-induced cardioprotection is mediated by protein kinase C (PKC). The Langendorff model was used, and isolated perfused rat hearts were separated into untreated, isoflurane, chelerythrine (PKC inhibitor) plus isoflurane, and chelerythrine groups. All hearts ...

BACKGROUND: The "euthyroid sick syndrome" may intensify dysfunction of the heart during acute myocardial ischemia. The present research was undertaken to outline the effects of preischemic short-term triiodothyronine (T3) administration on hemodynamic function and metabolism of the myocardium during reperfusion. MATERIAL/METHODS: Thirty-six isolated working rat hearts were assigned to three ...

Although exposure to broad band (0.2-20 MHz) electromagnetic fields (EMF) is part of the treatment of several diseases, little is known as to their effects on myocardial protein expression and resistance to ischemia-reperfusion (I/R). We exposed Sprague-Dawley rats to either high (H, 10 min/day at 200 V/m, 36.1 microT) or ...

BACKGROUND: Lidocaine is frequently used as an agent to treat ventricular arrhythmias associated with acute myocardial ischaemia. Lidocaine is a potent blocker not only of sodium channels, but also of ATP-sensitive potassium channels. The opening of these channels is a key mechanism of ischaemic preconditioning. We investigated the hypothesis that ...

The antiapoptotic protein Bcl-2 is targeted to the mitochondria, but it is uncertain whether Bcl-2 affects only myocyte survival after ischemia, or whether it also affects metabolic functions of mitochondria during ischemia. Hearts from mice overexpressing human Bcl-2 and from their wild-type littermates (WT) were subjected to 24 minutes of ...

HYPOTHESIS: Recent findings indicate that intraintestinal pancreatic protease inhibition before superior mesentery artery occlusion (SMAO) attenuates inflammation and symptoms of shock. Herein we examine the effectiveness of delayed intestinal protease inhibition during reperfusion after SMAO. SUBJECTS: Three groups of male Wistar rats were studied: a nonshock sham group and 2 ...

We investigated whether transient systemic ischemia can precondition the heart against the ensuing ischemic insult. Rabbits were randomly divided into systemic ischemic preconditioning (SIP), hemodilution (HD) and control (C) groups. SIP was induced by rapidly withdrawing blood from femoral artery and maintaining the mean artery pressure at 50 mmHg for ...

Pathological changes of cerebral microvessels in transient ischemia were investigated by scanning electron microscopy of vascular corrosion casts. Wistar rats were treated with middle cerebral artery (MCA) occlusion for 30 min, 1 h, 3 h, 4 h, 5 h or 7 h and subsequent reperfusion for 2 h. The ultrastructures ...

PURPOSE: Though nitric oxide has many favorable protective effects on donor lungs, it may also have cytotoxic side effects. In this regard, we investigated whether administration of nitroglycerine, a nitric oxide donor, could minimize ischemia-reperfusion injury in an isolated rat lung reperfusion model. MATERIALS AND METHODS: Thirty-five Sprague-Dawley rats were ...

PURPOSE: The cause of the coagulopathy seen with supraceliac aortic cross-clamping (SC AXC) is unclear. SC AXC for 30 minutes results in both clotting factor consumption and activation of fibrinolytic pathways. This study was undertaken to define the hemostatic alterations that occur with longer intervals of SC AXC. METHODS: Seven ...

OBJECTIVE: Cardiopulmonary bypass and surgical stress are accompanied by a systemic inflammatory response and activation of coagulation. Thrombin forms fibrin and activates platelets and neutrophils. Consequently, disseminated microthrombosis might increase capillary vascular resistance and thus impair reperfusion. We hypothesized that recombinant hirudin, a direct inhibitor of thrombin, could attenuate coagulation ...

This study examines the hypothesis that ischemic or pharmacologic preconditioning improves postischemic mitochondrial function by attenuating oxidation of mitochondrial proteins. Isolated rat hearts were perfused for 38 min preischemia, followed by 25 min global ischemia and then 60 min reperfusion. Hearts were preconditioned by two episodes of 3 min global ...

OBJECTIVE: To evaluate effects of graded intestinal hypoperfusion and reperfusion on intestinal metabolic parameters as assessed by a modified continuous saline tonometry technique. MATERIALS: Twelve barbiturate-anaesthetized female pigs. METHODS: Measurements were performed prior to and during three predefined levels of superior mesenteric mean arterial blood pressure (P(SMA) 70, 50 and ...

BACKGROUND: Lung ischemia-reperfusion injury occurs after lung transplantation and various clinical procedures. Recently, apoptosis was reported to be induced after ischemia-reperfusion. We investigated the effects of inhaled nitric oxide (NO) on lung ischemia-reperfusion and apoptosis after ischemia-reperfusion. METHODS: As a control group, the left pulmonary hilum of Japanese white rabbits ...

This study was undertaken to explore the myocardioprotective effects of the combination of ischemic preconditioning (IP) with hypothermia and St.II Thomas crystalloid cardioplegic solution (CCS) on immature hearts in the rabbit. Isolated immature rabbit hearts were perfused with Krebs-Henseleit bicarbonate buffer on Langendorff apparatus. In experiment 1, 24 hearts were ...

Transient inhibition of gap junction (GJ)-mediated communication with heptanol during myocardial reperfusion limits infarct size. However, inhibition of cell coupling in normal myocardium may be arrhythmogenic. The purpose of this study was to test the hypothesis that the consequences of GJ inhibition may be magnified in reperfused myocardium compared with ...

Previous work has shown that the endogenous cystathionine gamma-synthase (CSE)/hydrogen sulfide (H(2)S) pathway participates in the regulation of cardiac contraction. We hypothesized that the pathway might participate in the pathophysiological regulation of ischemic heart disease. Isoproterenol injection of rat hearts induced a myocardial ischemic injury model, with reduced myocardial and ...

BACKGROUND: We have previously shown that metabolic arrest induced with ATP-regulated potassium channel openers (PCOs) can improve lung preservation by adding Aprikalim (a PCO, Rhone-Poulene Roher) to modified Euro-Collins solution for pulmonary artery flush. Because the membrane hyperpolarizing effects of a PCO potentially competes with the depolarizing effects of a ...

Ischemia-reperfusion injury plays a major role in graft dysfunction following transplantation. Extensive research has demonstrated that nitric oxide (NO) plays a fundamental role to protect the heart against this injury. Consequently, we quantified NO synthase (NOS) isoform protein levels in a rat heart transplant model during short and prolonged reperfusion ...

Topical administration of nitric oxide (NO) by inhalation is currently used as therapy in various pulmonary diseases, but preconditioning with NO to ameliorate lung ischemia/reperfusion (I/R) injury has not been fully evaluated. In this study, we investigated the effects of NO inhalation on functional pulmonary parameters using an in situ ...

Cardiac troponin I (cTnI) degradation has been noted in the stunned myocardium of rodents after ischemia and reperfusion and is one proposed mechanism for the decreased left ventricular (LV) contractility in postischemic hearts. cTnI degradation has been best described after reperfusion of the ischemic myocardium. The effect of ischemia, independent ...

BACKGROUND: Recent studies in adult hearts have indicated that KATP channels in the inner mitochondrial membrane are responsible for the protection. And we investigated whether opening of mitochondrial KATP channels (mKATP) could provide myocardial protection for immature rabbits and determined its role in cardioprotection. METHODS: Thirty-four 3-4-week-old rabbits, weighing 300 ...

OBJECTIVES: During thoracoabdominal aortic aneurysm repair, prolonged compromise of spinal cord blood supply can result in irreversible spinal cord injury. This study investigated the impact of mild hypothermia during aortic cross-clamping on postoperative paraplegia in a chronic porcine model. METHODS: The thoracic aorta was exposed and cross-clamped in 30 juvenile ...

Poly(ADP-ribose) polymerase (PARP) activation plays a key role in free radical-induced injury in the context of systemic inflammation and ischemia/reperfusion. In the present preclinical study, we investigated the effects of INO-1001, a novel PARP inhibitor, on cardiac and pulmonary function during reperfusion in an experimental model of cardioplegic arrest and ...

BACKGROUND: Expression of Bcl-2 family proteins and activation of terminal caspase 3 are important for ischemia-reperfusion-induced apoptosis. Bad and Bax are pro-apoptotic proteins, whereas, phosphorylation of Bad inhibits its binding to and inactivation of anti-apoptotic Bcl-2. Thus, decreases in phospho-Bad would be proapoptotic. We investigated if blood (BCP) or crystalloid ...

BACKGROUND: We investigated the influence of deep hypothermia (4 degrees C) during ischemia-reperfusion in the isolated rat heart model. METHODS: Isolated, perfused rat hearts underwent either 30 minutes of normothermic ischemia (control group) or 30 minutes of hypothermic ischemia (hypothermia-treated group), followed by 30 minutes of reperfusion in both groups. ...

Diagnostic ultrasound (US) is reported to increase intracellular oxidative stress in vitro. Increased oxidative stress mediated ischemia-reperfusion injury in the microcirculation. To examine the effects of US in hamster cheek pouch microcirculation during baseline and ischemia and reperfusion (I/R), I/R injury was provoked in the cheek pouch under "sham" (transducer ...

Erythropoietin (EPO), the principal hematopoietic cytokine that regulates mammalian erythropoiesis, exhibits diverse cellular effects in non-hematopoietic tissues. The physiologic functions of EPO are mediated by its specific cell-surface receptor EPOR. In this study, we demonstrate EPOR expression in adult rat cardiac myocytes and examine the direct effects of EPO on ...

BACKGROUND: Drugs that selectively block nitric oxide synthase (NOS) 2 enzyme activity by inhibiting dimerization of NOS2 monomers have recently been developed. METHODS AND RESULTS: To investigate whether selective inhibition of NOS2 is cardioprotective, rats were pretreated for 2 days with BBS2, an inhibitor of NOS2 dimerization, at 15 mg/kg ...

1. We determined (1) the inhibitory potency of zoniporide against the native Na(+)/H(+) exchanger isoform 1 (NHE1) that is expressed in adult rat ventricular myocytes and platelets, and (2) the cardioprotective efficacy of zoniporide in isolated, blood-perfused adult rat hearts subjected to cardioplegic arrest, hypothermic ischaemia (150 min at 25 ...

BACKGROUND: Evidence from humans suggests that fatty acid translocase (FAT)/CD36 deficiency can lead to functionally and/or energetically compromised hearts, but the data are equivocal, and the subject remains controversial. In this report we assessed the contribution of FAT/CD36 to overall fatty acid oxidation rates in the intact heart and determined ...

Histamine H3 receptors are involved in regulating the release of norepinephrine (NE), in both central and peripheral nervous systems. We investigated the effect of R-alpha-methylhistamine (R-HA), a selective H3 receptor agonist, and thioperamide (Thiop), a selective H3 receptor antagonist, on ischemia/reperfusion-induced changes in carrier-mediated NE release and cardiac function in ...

Channel patency and a cavito-myocardial pressure gradient are prerequisites for one potential mechanism of transmyocardial laser revascularization (TMLR), namely indirect (non-coronary) myocardial perfusion. We assessed the effect of TMLR combined with vascular endothelial growth factor (VEGF) on the myocardial tissue pressure (MTP) in chronic ischemia questioning firstly, whether transmural pressure ...

This work aims at exploring changes in cellular energetics by exploiting the Pasteur effect. We assumed that lactate overproduction arising from antimycin A-induced inhibition of mitochondrial respiration (delta-lactate = stimulated [lactate] -basal [lactate]) is indicative of the energy provided aerobically by the cell. Rat embryonal cardiomyocytes (H9c2), incubated with 2 ...

OBJECTIVE: To assess the effects of moderate intraischemic hypothermia on neurophysiological parameters in an epidural balloon compression model in rats and to correlate the results with magnetic resonance imaging and histological findings. METHODS: Neurophysiological monitoring included laser Doppler flow, tissue partial oxygen pressure, and intracranial pressure measurements and electroencephalographic assessments ...

To assess the tolerance of rats that developed from birth in intermittent hypoxia (IH) to myocardial ischemia and reperfusion, we set up a reproducible model in our laboratory. IH rats were raised 60 days from birth in a hypobaric chamber at 5000 m for 6 h daily, while controls were ...

OBJECTIVE: Na+/H+ exchanger (NHE) blockade fails as reperfusion therapy in patients with acute myocardial infarction. In experimental studies, the reports on the efficacy of NHE blockade only during reperfusion are inconsistent. Differences in the severity of ischemia and in drug delivery may explain these inconsistencies. Little is known about the ...

This study's rationale was that the expression and activity of aspartate transporters in hypertrophied hearts might be different from normal hearts, which could affect the use of aspartate in myocardial protection of hypertrophied hearts. mRNA expression of system X(ag)(-) transporters in hearts from normal (Wistar Kyoto) and hypertrophied (spontaneously hypertensive ...

BACKGROUND: Surgically induced ischemia in the arrested heart can result in changes in the mechanical properties of the myocardium. Regions of ischemia may be characterized based on the amount of epicardial deformation for a given load. Computer aided speckle interferometry (CASI), which tracks the movement of clusters of particles, is ...

In dogs, isotonic saline at 0-4 degrees C, flushed into the aorta at a rate of 1-2 L/min, with drainage of the vena cava, can achieve deep to profound hypothermia of vital organs at a cooling rate of up to 3 degrees C per minute. This achieves preservation of viability ...

In addition to the generation from specific nitric-oxide (NO) synthases, NO formation from nitrite occurs in ischemic tissues, such as the heart. Although NO binding to heme-centers is the basis for NO-mediated signaling as occurs through guanylate cyclase, it is not known if this process is triggered with physiologically relevant ...

Ischemia/reperfusion injury plays an important role in the pathogenesis of abdominal compartment syndrome, which is characterized by increased intra-abdominal pressure. The aim of this study was to investigate whether octreotide, a synthetic somatostatin analogue, improves the reperfusion injury after decompression of acute abdominal hypertension. This study was carried out in ...