BACKGROUND: Aim of the study was to find out which myocardial repolarization parameters predict reperfusion ventricular tachycardia and fibrillation (VT/VF) and determine how these parameters express in ECG. METHODS: Coronary occlusion and reperfusion (30/30min) was induced in 24 cats. Local activation and end of repolarization times (RT) were measured in 88 intramyocardial leads. Computer simulations of precordial electrograms were performed. RESULTS: Reperfusion VT/VF developed in 10 animals. Arrhythmia-susceptible animals had longer RTs in perfused areas [183(177;202) vs 154(140;170) ms in susceptible and resistant animals, respectively, P<0.05]. In logistic regression analysis, VT/VFs were associated with prolonged RTs in the perfused area (OR 1.068; 95% CI 1.012-1.128; P=0.017). Simulations demonstrated that prolonged repolarization in the perfused/border zone caused precordial terminal T-wave inversion. CONCLUSIONS: The reperfusion VT/VFs were independently predicted by the longer RT in the perfused zone, which was reflected in the terminal negative phase of the electrocardiographic T-wave.

• Keywords
• Arrhythmias, ECG, Ischemia-reperfusion, Repolarization, Simulation,
• MeSH
• Electrocardiography * MeSH
• Ventricular Fibrillation physiopathology   MeSH
• Cats MeSH
• Tachycardia, Ventricular physiopathology   MeSH
• Disease Models, Animal MeSH
• Reperfusion Injury physiopathology   MeSH
• Animals MeSH
• Check Tag
• Cats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

A key component of cardiac ischemia-reperfusion injury (IRI) is the increased generation of reactive oxygen species, leading to enhanced inflammation and tissue dysfunction in patients following intervention for myocardial infarction. In this study, we hypothesized that oxidative stress, due to ischemia-reperfusion, induces senescence which contributes to the pathophysiology of cardiac IRI. We demonstrate that IRI induces cellular senescence in both cardiomyocytes and interstitial cell populations and treatment with the senolytic drug navitoclax after ischemia-reperfusion improves left ventricular function, increases myocardial vascularization, and decreases scar size. SWATH-MS-based proteomics revealed that biological processes associated with fibrosis and inflammation that were increased following ischemia-reperfusion were attenuated upon senescent cell clearance. Furthermore, navitoclax treatment reduced the expression of pro-inflammatory, profibrotic, and anti-angiogenic cytokines, including interferon gamma-induced protein-10, TGF-β3, interleukin-11, interleukin-16, and fractalkine. Our study provides proof-of-concept evidence that cellular senescence contributes to impaired heart function and adverse remodeling following cardiac ischemia-reperfusion. We also establish that post-IRI the SASP plays a considerable role in the inflammatory response. Subsequently, senolytic treatment, at a clinically feasible time-point, attenuates multiple components of this response and improves clinically important parameters. Thus, cellular senescence represents a potential novel therapeutic avenue to improve patient outcomes following cardiac ischemia-reperfusion.

• Keywords
• cardiac, ischemia-reperfusion, remodeling, senescence, senolytic,
• MeSH
• Humans MeSH
• Reperfusion Injury metabolism   MeSH
• Cellular Senescence physiology   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

OBJECTIVE: This experiment evaluated the influence of erythropoietin (Epo) in an animal model of uterine ischemia reperfusion using the quoting established protocol. DESIGN: The effects of erythropoietin treatment were evaluated by mean uterus inflammation (UI) lesions. UI lesions were determined at the 60th reperfusion min (for groups A and C) and at the 120th reperfusion min (for groups B and D). Groups A and B received no drugs, whereas rats from groups C and D were administered with erythropoietin. METHODS: 40 rats of mean mass 247.7 g were employed for the study. RESULTS: Epo administration non-significantly decreased the UI scores [without lesions] by 0.1 [-0.6244129 - 0.4244129] (p = 0.6294)). Reperfusion time kept non-significantly increased the UI scores by [without lesions] 0.15 [-0.60230385 - 0.50230385] (p = 0.5782). Together, Epo administration combined with reperfusion time non-significantly decreased the UI scores by [without lesions] 0.0727273 [-0.3886782 - 0.2432236] (p = 0.6439). CONCLUSIONS: Epo administration whether it interacted or not with reperfusion time non-significantly short-term decreased the UI lesions scores. Perhaps, a longer study time than two hours or a higher Epo dose may provide more significant effects.

• Keywords
• erythropoietin, ischemia, uterus inflammation reperfusion.,
• MeSH
• Antioxidants pharmacology   MeSH
• Erythropoietin pharmacology   MeSH
• Disease Models, Animal MeSH
• Rats, Wistar MeSH
• Reperfusion Injury prevention & control   MeSH
• Uterus blood supply   MeSH
• Inflammation drug therapy   MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Antioxidants MeSH
• Erythropoietin MeSH

Melatonin is assumed to confer cardioprotective action via antioxidative properties. We evaluated the association between ventricular tachycardia and/or ventricular fibrillation (VT/VF) incidence, oxidative stress, and myocardial electrophysiological parameters in experimental ischemia/reperfusion under melatonin treatment. Melatonin was given to 28 rats (10 mg/kg/day, orally, for 7 days) and 13 animals received placebo. In the anesthetized animals, coronary occlusion was induced for 5 min followed by reperfusion with recording of unipolar electrograms from ventricular epicardium with a 64-lead array. Effects of melatonin on transmembrane potentials were studied in ventricular preparations of 7 rats in normal and "ischemic" conditions. Melatonin treatment was associated with lower VT/VF incidence at reperfusion, shorter baseline activation times (ATs), and activation-repolarization intervals and more complete recovery of repolarization times (RTs) at reperfusion (less baseline-reperfusion difference, ΔRT) (p < 0.05). Superoxide dismutase (SOD) activity was higher in the treated animals and associated with ΔRT (p = 0.001), whereas VT/VF incidence was associated with baseline ATs (p = 0.020). In vitro, melatonin led to a more complete restoration of action potential durations and resting membrane potentials at reoxygenation (p < 0.05). Thus, the antioxidative properties of melatonin were associated with its influence on repolarization duration, whereas the melatonin-related antiarrhythmic effect was associated with its oxidative stress-independent action on ventricular activation.

• Keywords
• arrhythmia, depolarization, ischemia, melatonin, oxidative stress, reperfusion, repolarization,
• MeSH
• Anti-Arrhythmia Agents pharmacology   MeSH
• Antioxidants pharmacology   MeSH
• Electrophysiological Phenomena drug effects   MeSH
• Electrocardiography drug effects   MeSH
• Ventricular Fibrillation drug therapy   MeSH
• Rats MeSH
• Melatonin pharmacology   MeSH
• Rats, Wistar MeSH
• Myocardial Reperfusion Injury drug therapy   MeSH
• Reperfusion Injury drug therapy   MeSH
• Arrhythmias, Cardiac drug therapy   MeSH
• Cardiac Electrophysiology methods   MeSH
• Heart Ventricles drug effects   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Arrhythmia Agents MeSH
• Antioxidants MeSH
• Melatonin MeSH

We tested whether treatment with exogenous L-arginine, the precursor of nitric oxide (NO), could protect the skeletal muscle from ischemia/reperfusion (I/R) injury. A rabbit hindlimb I/R model (2.5 h ischemia/2 h reperfusion) was used. Morphological changes were elucidated by morphometry. Plasma concentrations of malondialdehyde (pMDA), as well as L-arginine and L-citrulline content in the plasma and skeletal muscle were measured. I/R injury in the skeletal muscle was manifested by development of prominent interstitial edema (fraction of interfiber area was 26.23% vs 15.09% in sham operated control, p < .005) and severe microvascular constriction (capillary area was 11.41 microns2 vs 16.92 in control, p <.005). These changes were accompanied by increased pMDA levels, indicating a process of lipid peroxidation in the cell membranes. L-arginine treatment (4 mg/kg/min intravenously, for 1 h, infusion initiated 30 min before reperfusion) caused an intracellular accumulation of this amino acid in the SM. Intracellular concentrations of L-citrulline increased (201.0 mumol/dm3 after reperfusion vs 176.0 before ischemia onset, p < .005), suggesting stimulated endogenous NO synthesis. L-arginine treatment protected capillary constriction (capillary area was 17.64 microns2 vs 11.41 in the untreated animals, p < .0005) and reduced interstitial edema after reperfusion (fraction of interfiber area was 17.80% vs 26.23 in untreated animals, p < 0.005). The protective effect of L-arginine treatment on I/R injury of SM may be related to its ability to prevent microvascular constriction and reduce permeability disorders by the stimulation of endogenous NO production.

• MeSH
• Arginine metabolism   therapeutic use   MeSH
• Muscle, Skeletal blood supply   metabolism   pathology   MeSH
• Rabbits MeSH
• Reperfusion Injury drug therapy   metabolism   pathology   MeSH
• Hindlimb blood supply   MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Arginine MeSH

Gut ischemia and reperfusion (IR), e.g. in small bowel transplantation or during resuscitation, may result in severe impairment of the intestinal microcirculation. Potential sequelae are mucosal damage, loss of intestinal barrier function, bacterial translocation, systemic inflammation, multiple organ failure and death. We hypothesized a protective role for extracellular adenosine signalling in intestinal IR injury. Using intravital microscopy we investigated the effects of the adenosine receptor (AR) agonist NECA (5'-N-ethyl carboxamide adenosine) on leukocyte-endothelial interactions and capillary perfusion in the intestinal microcirculation following intestinal IR. Six groups of Lewis rats (n = 44) were studied: control, NECA (5'-N-ethyl carboxamide adenosine), IR (30 minutes of intestinal ischemia, 2 hours of reperfusion), IR + NECA, IR + NECA + MRS1754 (A(2B)AR antagonist), IR + NECA + DPCPX (A(1)AR antagonist). All substances were administered i.v. immediately after declamping of the superior mesenteric artery. Intravital microscopy was performed after 2 hours of reperfusion. Following IR we observed a significant increase of leukocyte adhesion in the intestinal submucosal venules and a reduced capillary perfusion within the muscular layers. NECA reduced leukocyte activation and improved capillary perfusion significantly. Administration of A(2B)AR antagonist completely reversed the NECA effect, whereas A(1)AR inhibition only partially abolished the action of NECA. The data support the hypothesis that adenosine signalling is involved in intestinal IR injury. A(2B)AR may be more important than A(1)AR because A(2B)AR inhibition by MRS1754 completely reversed the effect of the adenosine receptor agonist NECA.

• Keywords
• Adenosine, adenosine receptor, capillary perfusion, functional capillary density (FCD), intestine, intravital microscopy, ischemia, leukocyte adhesion, microcirculation, reperfusion,
• MeSH
• Rats MeSH
• Microcirculation drug effects   MeSH
• Disease Models, Animal MeSH
• Rats, Inbred Lew MeSH
• Receptors, Purinergic P1 genetics   metabolism   MeSH
• Reperfusion Injury MeSH
• Intestines blood supply   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Receptors, Purinergic P1 MeSH

Ischemia reperfusion injury is a complex process consisting of a seemingly chaotic but actually organized and compartmentalized shutdown of cell function, of which oxidative stress is a key component. Studying oxidative stress, which results in an imbalance between reactive oxygen species (ROS) production and antioxidant defense activity, is a multi-faceted issue, particularly considering the double function of ROS, assuming roles as physiological intracellular signals and as mediators of cellular component damage. Herein, we propose a comprehensive overview of the tools available to explore oxidative stress, particularly in the study of ischemia reperfusion. Applying chemistry as well as biology, we present the different models currently developed to study oxidative stress, spanning the vitro and the silico, discussing the advantages and the drawbacks of each set-up, including the issues relating to the use of in vitro hypoxia as a surrogate for ischemia. Having identified the limitations of historical models, we shall study new paradigms, including the use of stem cell-derived organoids, as a bridge between the in vitro and the in vivo comprising 3D intercellular interactions in vivo and versatile pathway investigations in vitro. We shall conclude this review by distancing ourselves from "wet" biology and reviewing the in silico, computer-based, mathematical modeling, and numerical simulation options: (a) molecular modeling with quantum chemistry and molecular dynamic algorithms, which facilitates the study of molecule-to-molecule interactions, and the integration of a compound in a dynamic environment (the plasma membrane...); (b) integrative systemic models, which can include many facets of complex mechanisms such as oxidative stress or ischemia reperfusion and help to formulate integrated predictions and to enhance understanding of dynamic interaction between pathways.

• Keywords
• ROS, animal models, antioxidant factors, ischemia-reperfusion injury, molecular modeling models, organoids, oxidative stress,
• MeSH
• Cell Line MeSH
• Humans MeSH
• Disease Models, Animal * MeSH
• Models, Molecular MeSH
• Oxidative Stress * MeSH
• Reactive Oxygen Species MeSH
• Reperfusion Injury metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Reactive Oxygen Species MeSH

Reactive oxygen species and other oxidants are involved in the mechanism of postischemic contractile dysfunction, known as myocardial stunning. The present study investigated the oxidative modification of cardiac proteins in isolated Langendorff-perfused rabbit hearts subjected to 15 min normothermic ischemia followed by 10 min reperfusion. Reperfusion under these conditions resulted in only 61.8+/-2.7 % recovery of developed pressure relative to preischemic values and this mechanical dysfunction was accompanied by oxidative damage to cardiac proteins. The total sulfhydryl group content was significantly reduced in both ventricle homogenates and mitochondria isolated from stunned hearts. Fluorescence measurements revealed enhanced formation of bityrosines and conjugates of lipid peroxidation-end products with proteins in cardiac homogenates, whereas these parameters were unchanged in the mitochondrial fraction. Reperfusion did not alter protein surface hydrophobicity, as detected by a fluorescent probe 1-anilino-8-naphthalenesulfonate. Our results indicate that oxidation of proteins in mitochondria and possibly in other intracellular structures occurs during cardiac reperfusion and might contribute to ischemia-reperfusion injury.

• MeSH
• Myocardial Ischemia metabolism   MeSH
• Rabbits MeSH
• Oxidation-Reduction MeSH
• Lipid Peroxidation physiology   MeSH
• Proteins metabolism   MeSH
• Myocardial Reperfusion methods   MeSH
• Myocardial Reperfusion Injury metabolism   MeSH
• Heart physiology   MeSH
• In Vitro Techniques MeSH
• Animals MeSH
• Check Tag
• Rabbits MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Proteins MeSH

BACKGROUND: We evaluated the association of reperfusion quality and different patterns of achieved reperfusion with clinical and radiological outcomes in the ESCAPE NA1 trial. METHODS: Data are from the ESCAPE-NA1 trial. Good clinical outcome [90-day modified Rankin Scale (mRS) 0-2], excellent outcome (90-day mRS0-1), isolated subarachnoid hemorrhage, symptomatic hemorrhage (sICH) on follow-up imaging, and death were compared across different levels of reperfusion defined by expanded Treatment in Cerebral Infarction (eTICI) Scale. Comparisons were also made between patients with (a) first-pass eTICI 2c3 reperfusion vs multiple-pass eTICI 2c3; (b) final eTICI 2b reperfusion vs eTICI 2b converted-to-eTICI 2c3; (c) sudden reperfusion vs gradual reperfusion if >1 pass was required. Multivariable logistic regression was used to test associations of reperfusion grade and clinical outcomes. RESULTS: Of 1037 included patients, final eTICI 0-1 was achieved in 46 (4.4%), eTICI 2a in 76 (7.3%), eTICI 2b in 424 (40.9%), eTICI 2c in 284 (27.4%), and eTICI 3 in 207 (20%) patients. The odds for good and excellent clinical outcome gradually increased with improved reperfusion grades (adjOR ranging from 5.7-29.3 and 4.3-17.6) and decreased for sICH and death. No differences in outcomes between first-pass versus multiple-pass eTICI 2c3, eTICI 2b converted-to-eTICI 2c3 versus unchanged eTICI 2b and between sudden versus gradual eTICI 2c3 reperfusion were observed. CONCLUSION: Better reperfusion degrees significantly improved clinical outcomes and reduced mortality, independent of the number of passes and whether eTICI 2c3 was achieved suddenly or gradually.

• Keywords
• Ischemic stroke, endovascular treatment, first-pass effect, mechanical thrombectomy, reperfusion grade,
• MeSH
• Middle Aged MeSH
• Humans MeSH
• Reperfusion * methods   MeSH
• Aged MeSH
• Subarachnoid Hemorrhage therapy   diagnostic imaging   mortality   MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Randomized Controlled Trial MeSH

Gastric mucus plays an important role in gastric mucosal protection. Apart from its "barrier" function, it has been demonstrated that mucus protects gastric epithelial cells against toxic oxygen metabolites derived from the xanthine/ xanthine oxidase system. In this study, we investigated the effect of malotilate and sucralfate (mucus production stimulators) and N-acetylcysteine (mucolytic agent) on ischemia/reperfusion-induced gastric mucosal injury. Gastric ischemia was induced by 30 min clamping of the coeliac artery followed by 30 min of reperfusion. The mucus content was determined by the Alcian blue method. Sucralfate (100 mg/kg), malotilate (100 mg/kg), and N-acetylcysteine (100 mg/kg) were given orally 30 min before surgery. Both sucralfate and malotilate increased the mucus production in control rats. On the other hand, N-acetyloysteine significantly decreased mucus content in control (sham) group. A significant decrease of mucus content was found in the control and the N-acetylcysteine pretreated group during the period of ischemia. On the other hand, sucralfate and malotilate prevented the decrease the content of mucus during ischemia. A similar result can be seen after ischemia/reperfusion. In the control group and N-acetylcysteine pretreated group a significant decrease of adherent mucus content was found. However, sucralfate and malotilate increased mucus production (sucralfate significantly). Sucralfate and malotilate also significantly protected the gastric mucosa against ischemia/reperfusion-induced injury. However, N-acetylcysteine significantly increased gastric mucosal injury after ischemia/reperfusion. These results suggest that gastric mucus may be involved in the protection of gastric mucosa after ischemia/reperfusion.

• MeSH
• Mucus metabolism   MeSH
• Rats MeSH
• Rats, Wistar MeSH
• Reperfusion Injury metabolism   MeSH
• Gastric Mucosa metabolism   MeSH
• Stomach blood supply   pathology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH