Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nitric oxide (NO) has been implicated as a cardioprotective agent during ischemia/reperfusion (I/R), but the mechanism of protection is unknown. Oxidant stress contributes to cell death in I/R, so we tested whether NO protects by attenuating oxidant stress. Cardiomyocytes and murine embryonic fibroblasts were administered NO (10-1200 nM) during simulated ischemia, and cell death was assessed during reperfusion without NO. In each case, NO abrogated cell death during reperfusion. Cells overexpressing endothelial NO synthase (NOS) exhibited a similar protection, which was abolished by the NOS inhibitor N(omega)-nitro-l-arginine methyl ester. Protection was not mediated by guanylate cyclase or the mitochondrial K(ATP) channel, as inhibitors of these systems failed to abolish protection. NO did not prevent decreases in mitochondrial potential, but cells protected with NO demonstrated recovery of potential at reperfusion. Measurements using C11-BODIPY reveal that NO attenuates lipid peroxidation during ischemia and reperfusion. Measurements of oxidant stress using the ratiometric redox sensor HSP-FRET demonstrate that NO attenuates protein oxidation during ischemia. These findings reveal that physiological levels of NO during ischemia can attenuate oxidant stress both during ischemia and during reperfusion. This response is associated with a remarkable attenuation of cell death, suggesting that ischemic cell death may be a regulated event.
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PMID:Nitric oxide during ischemia attenuates oxidant stress and cell death during ischemia and reperfusion in cardiomyocytes. 1764 May 69

The liver is damaged by sustained ischemia in liver transplantation, and the reperfusion after ischemia results in further functional impairment. Ozone oxidative preconditioning (OzoneOP) protected the liver against ischemia/reperfusion (I/R) injury. The aim of this study was to investigate the role of A(1) adenosine receptor on the protective actions conferred by OzoneOP in hepatic I/R. By using a specific agonist and antagonist of the A(1) subtype receptor (2-chloro N6 cyclopentyladenosine, CCPA and 8-cyclopentyl-1,3-dipropylxanthine, DPCPX respectively), we studied the role of A(1) receptor in the protective effects of OzoneOP on the liver damage, nitiric oxide (NO) generation, adenosine deaminase activity and preservation of the cellular redox balance. Immunohistochemical analysis of nuclear factor-kappa B (NF-kappaB), tumor necrosis factor alpha (TNF-alpha) and heat shock protein-70 (HSP-70) was performed. OzoneOP prevented and/or ameliorated ischemic damage. CCPA showed a similar effect to OzoneOP + I/R group. A(1)AR antagonist DPCPX blocked the protective effect of OzoneOP. OzoneOP largely reduced the intensity of the p65 expression, diminished TNF-alpha production, and promoted a reduction in HSP-70 immunoreactivity. In summary, OzoneOP exerted protective effects against liver I/R injury through activation of A(1) adenosine receptors (A(1)AR). Adenosine and (.)NO produced by OzoneOP may play a role in the pathways of cellular signalling which promote preservation of the cellular redox balance, mitochondrial function, glutathione pools as well as the regulation of NF-kappaB and HSP-70.
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PMID:Ozone oxidative preconditioning is mediated by A1 adenosine receptors in a rat model of liver ischemia/ reperfusion. 1792 80

It is established that the chronic administration of Rhodiola rosea extract (RRE) in a single daily dose of 1 ml/kg (p.o.) during 8 days increased the resistance of myocardium with respect to the cardiotoxic action of isoproterenol and the arrhythmogenic action of epinephrine in rats. Pretreatment with RRE prevented the stressor cardiac damages, as measured by 99mTc-pyrophosphate accumulation in the heart. The cardioprotective action of RRE was maximum after 5-day administration. The antiarrhythmic effect of the adaptogen was maximum after 8-day administration. It was found that p-tyrosol also exhibited antiarrhythmic and cardioprotective properties. Pretreatment with RRE decreased the infarction size/risk area ratio during the coronary artery occlusion and reperfusion in vivo. The chronic administration of RRE increased th e tolerance of the isolated perfused rat heart to the pathogenic action of global ischemia and reperfusion. Pretreatment with RRE not only prevented the occurrence of arrhythmias, but also abolished cardiac electrical instability in rats with postinfarction cardiac sclerosis. It has been found that the chronic administration of RRE (1 ml/kg, p.o., over 8 days) increased the level beta-endorphin in rat blood plasma and the content of leu-enkephalin in myocardial tissue. Naloxone (2 mg/kg) abolished cardioprotective and antiarrhythmic effect of the adaptogen. It was suggested that both RRE effects depend on the occupancy of opioid receptors by endogenous opioid peptides. It has been found that the sympathetic nervous system is involved in the development of antiarrhythmic effect of RRE, while HSP-70 is not involved in the cardioprotective and antiarrhythmic effect of adaptogen. It is concluded that the mechanism of cardioprotective and antiarrhythmic action of RRE needs further investigation.
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PMID:[Cardioprotective and antiarrhythmic properties of Rhodiolae roseae preparations]. 1807 10

The activation of the immunologic system plays an immportant role in the initiation of atherogenesis, as shown in numerous studies. However the role of infectious agents in this process still remains controversial. The aim of this study was to investigate the involvement of heat shock protein as a link between infection and peripheral arterial disease. 31 patients suffering from lower limb ischemia were enrolled in the study. Patients were divided into 2 groups. Group I - patients with peripheral arterial disease, group II patients with diabetic macroangiopathy. The control group consisted of 11 healthy volunteers. Blood samples were taken from each participant in order to determine serum concentrations of anti Chlamydia pneumoniae, CMV and HSP 60/65 antibodies. Statistic analysis showed anti-C. pneumoniae IgG (p< 0.025) and anti-CMV IgG (p<0.0157) antibodies were significantly more frequent in both study groups in comparison with healthy controls. Antibodie levels were also found significantly higher than in controls. Mean concentration of anti-C. pneumoniae IgG in the study group was 69.67574 vs. 18.59722 [AU/ml] in the control group (p<0.01). Analogical anti CMV IgG levels in the study group were 337.6516 vs 121.3778 [AU/ml] in controls (p<0.025). Similar changes in antibody concentration were noticed for the C. pneumoniae IgA index. 0.835258 vs. 0.176333 (p< 0.005). Antibodies against HSP 60/65 were present in significantly higher titre (p<0.005). No significant differences in antibody levels were detected beteween groups I and II. The positive correlation between anti-C. pneumoniae Ig A (r=0.3910; p<0.03) and anti HSP 60/65 antibodies titre, as well as anti-C. pneumoniae Ig G (r= 0.7151; p<0.00009) and anti HSP 60/65 speaks for the heat shock protein involvement in atherosclerotic plaque development.
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PMID:[Role of chronic infection and heat shock proteins in peripheral arterial disease]. 1815 51

Henoch-Schonlein Purpura (HSP) is the most common systemic vasculitis in childhood. The diagnostic criteria include palpable purpura with at least one other manifestation -- abdominal pain, IgA deposition, arthritis or arthralgia, or renal involvement. Immune complex deposits result in necrosis of the wall of small- and medium-sized arteries with infiltration of tissue by neutrophils and deposition of nuclear fragments, a process called leukocytoclastic vasculitis (LCV). It is often associated with infections, medications, or tumors. It may coexist with or mimic Crohn's disease. Periumbilical and epigastric pain worsens with meals, from bowel angina. Bleeding is usually occult or, less commonly, associated with melena. Intussusception, the most common surgical complication, is usually ileo-ileo or ileo-colic. Perforations, usually ileal, may occur spontaneously or be associated with intussusception. Ultrasound, recommended as the first diagnostic test, and CT scans may show intussusception and asymmetric bowel wall thickening mainly involving the jejunum and ileum. There are a range of endoscopic findings including gastritis, duodenitis, ulceration, and purpura, with the second portion of the duodenum characteristically being involved more than the bulb. Intestinal biopsies show IgA deposition and LCV in the submucosal vessels. Superficial biopsies may show inflammation, ulceration, edema, hemorrhage, and vascular congestion, presumably due to vasculitis-induced mucosal ischemia. The efficacy of corticosteroids in preventing severe complications or relapses is controversial. The majority of patients, however, improve spontaneously.
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PMID:Gastrointestinal manifestations of Henoch-Schonlein Purpura. 1835 68

Cation chloride cotransporters have been reported to be expressed in neurons in the hippocampus and to regulate intracellular Cl(-) concentration. The neuron-specific K-Cl cotransporter 2 (KCC2) is necessary for maintaining the low intracellular chloride concentration required for the hyperpolarizing actions of GABA. In this study we examined the vulnerability of KCC2-containing neurons as well as the changes in the pattern of KCC2 distribution in the rat hippocampus following 15 min ischemia induced by four-vessel occlusion. Immunostaining for the 72 kDa heat shock protein (HSP-72) was used to investigate the extent of damage in neuronal populations previously shown to be vulnerable to ischemia. At 6-24 h after ischemia, when the pyramidal cells in the CA1 (subfield of cornu Ammonis) region showed no morphological signs of damage, a small rise of KCC2 immunoreactivity was already observed. After 2 days, when the CA1 pyramidal cells started to degenerate, a progressive downregulation of the KCC2 protein was visible. Interestingly, in the same areas, the parvalbumin containing interneurons showed no signs of ischemic damage, and KCC2 immunoreactivity was retained on their membrane surface. In CA1 pyramidal cells, the reduction in KCC2 expression may lead to an elevation of intracellular Cl(-) concentration, which causes a shift in equilibrium potential toward more positive levels. Consequently, the reduction of the inhibitory action of GABA through downregulation of KCC2 function may be involved in the pathomechanisms of delayed neuronal death in the CA1 subfield.
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PMID:Relationship between neuronal vulnerability and potassium-chloride cotransporter 2 immunoreactivity in hippocampus following transient forebrain ischemia. 1847 45

Hydrogen sulfide (H(2)S) is an endogenously produced gaseous signaling molecule with diverse physiological activity. The potential protective effects of H(2)S have not been evaluated in the liver. The purpose of the current study was to investigate if H(2)S could afford hepatoprotection in a murine model of hepatic ischemia-reperfusion (I/R) injury. Hepatic injury was achieved by subjecting mice to 60 min of ischemia followed by 5 h of reperfusion. H(2)S donor (IK1001) or vehicle were administered 5 min before reperfusion. H(2)S attenuated the elevation in serum alanine aminotransferase (ALT) by 68.6% and aspartate aminotransferase (AST) by 70.8% compared with vehicle group. H(2)S-mediated cytoprotection was associated with an improved balance between reduced glutathione (GSH) vs. oxidized glutathione (GSSG), an attenuated formation of lipid hydroperoxides, and an increased expression of thioredoxin-1 (Trx-1). Furthermore, H(2)S inhibited the progression of apoptosis after I/R injury by increasing the protein expression of heat shock protein (HSP-90) and Bcl-2. These results indicate that H(2)S protects the murine liver against I/R injury through an upregulation of intracellular antioxidant and antiapoptotic signaling pathways.
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PMID:Hydrogen sulfide attenuates hepatic ischemia-reperfusion injury: role of antioxidant and antiapoptotic signaling. 1856 6

The aim of this study was to investigate whether preconditioned local somatotheral stimulation (LSTS) protects the muscle and nerve against ischemia-reperfusion (I/R) injuries. Male rats were randomly assigned to normal, preconditioned LSTS only, and I/R-injured groups with or without LSTS preconditioning. I/R injuries of the lower limb were induced by rubber band wrapping, followed by measurements of gait function and nerve conduction, muscle pathology, serum enzymatic activity, and the expression of heat-shock protein 70 (HSP-70) in the gastrocnemius muscles. No significant change of neuromuscular function was found between LSTS (-) and LSTS (+) groups on the first day after I/R injury. In contrast, gait stride length, compound motor action potential, and serum creatine phosphokinase MM isoenzyme were significantly improved on the eighth day after one or two doses of preconditioned LSTS and subsequent I/R injury. Western blot analysis disclosed no significant change of HSP-70 expression in the muscle of I/R injured limbs between LSTS (-) and LSTS (+) groups. We conclude that preconditioned LSTS is a safe modality that improves the neuromuscular plasticity against I/R injured limbs, which provides a new strategy for I/R injury in clinical applications, such as intraoperative use of tourniquets.
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PMID:Protective effects of preconditioned local somatothermal stimulation on neuromuscular plasticity against ischemia--reperfusion injury in rats. 1863 18

Acute kidney injury evokes renal tubular cholesterol synthesis. However, the factors during acute kidney injury that regulate HMG CoA reductase (HMGCR) activity, the rate-limiting step in cholesterol synthesis, have not been defined. To investigate these factors, mice were subjected to 30 minutes of either unilateral renal ischemia or sham surgery. After 3 days, bilateral nephrectomy was performed and cortical tissue extracts were prepared. The recruitment of RNA polymerase II (Pol II), transcription factors (SREBP-1, SREBP-2, NF-kappaB, c-Fos, and c-Jun), and heat shock proteins (HSP-70 and heme oxygenase-1) to the HMGCR promoter and transcription region (start/end exons) were assessed by Matrix ChIP assay. HMGCR mRNA, protein, and cholesterol levels were determined. Finally, histone modifications at HMGCR were assessed. Ischemia/reperfusion (I/R) induced marked cholesterol loading, which corresponded with elevated Pol II recruitment to HMGCR and increased expression levels of both HMGCR protein and mRNA. I/R also induced the binding of multiple transcription factors (SREBP-1, SREBP-2, c-Fos, c-Jun, NF-kappaB) and heat shock proteins to the HMGCR promoter and transcription regions. Significant histone modifications (increased H3K4m3, H3K19Ac, and H2A.Z variant) at these loci were also observed but were not identified at either the 5' and 3' HMGCR flanking regions (+/-5000 bps) or at negative control genes (beta-actin and beta-globin). In conclusion, I/R activates the HMGCR gene via multiple stress-activated transcriptional and epigenetic pathways, contributing to renal cholesterol loading.
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PMID:Renal ischemia-induced cholesterol loading: transcription factor recruitment and chromatin remodeling along the HMG CoA reductase gene. 1909 62

Nephrotoxicity is the main side effect of antibiotics such as gentamicin. Preconditioning has been reported to protect against injuries as ischemia/reperfusion. The objective of the present study was to determine the effect of preconditioning with gentamicin on LLC-PK1 cells. Preconditioning was induced in LLC-PK1 cells by 24-h exposure to 2.0 mM gentamicin (G/IU). After 4 or 15 days of preconditioning, cells were again exposed to gentamicin (2.0 mM) and compared to untreated control or G/IU cells. Necrosis and apoptosis were assessed by acridine orange and HOESCHT 33346. Nitric oxide (NO) and endothelin-1 were assessed by the Griess method and available kit. Heat shock proteins were analyzed by Western blotting. After 15 days of preconditioning, LLC-PK1 cells exhibited a significant decrease in necrosis (23.5 +/- 4.3 to 6.5 +/- 0.3%) and apoptosis (23.5 +/- 4.3 to 6.5 +/- 2.1%) and an increase in cell proliferation compared to G/IU. NO (0.177 +/- 0.05 to 0.368 +/- 0.073 microg/mg protein) and endothelin-1 (1.88 +/- 0.47 to 2.75 +/- 0.53 pg/mL) production significantly increased after 15 days of preconditioning compared to G/IU. No difference in inducible HSP 70, constitutive HSC 70 or HSP 90 synthesis in tubular cells was observed after preconditioning with gentamicin. The present data suggest that preconditioning with gentamicin has protective effects on proximal tubular cells, that involved NO synthesis but not reduction of endothelin-1 or production of HSP 70, HSC 70, or HSP 90. We conclude that preconditioning could be a useful tool to prevent the nephrotoxicity induced by gentamicin.
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PMID:Gentamicin-induced preconditioning of proximal tubular LLC-PK1 cells stimulates nitric oxide production but not the synthesis of heat shock protein. 1946 82


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