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1.
Cytokine ; 176: 156536, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38325139

RESUMO

Chemokines, a family of chemotactic cytokines, mediate leukocyte migration to and entrance into inflamed tissue, contributing to the intensity of local inflammation. We performed an analysis of chemokine and immune cell responses to cardiac arrest (CA). Forty-two patients resuscitated from cardiac arrest were analyzed, and twenty-two patients who underwent coronary artery bypass grafting (CABG) surgery were enrolled. Quantitative antibody array, chemokines, and endotoxin quantification were performed using the patients blood. Analysis of CCL23 production in neutrophils obtained from CA patients and injected into immunodeficient mice after CA and cardiopulmonary resuscitation (CPR) were done using flow cytometry. The levels of CCL2, CCL4, and CCL23 are increased in CA patients. Temporal dynamics were different for each chemokine, with early increases in CCL2 and CCL4, followed by a delayed elevation in CCL23 at forty-eight hours after CA. A high level of CCL23 was associated with an increased number of neutrophils, neuron-specific enolase (NSE), worse cerebral performance category (CPC) score, and higher mortality. To investigate the role of neutrophil activation locally in injured brain tissue, we used a mouse model of CA/CPR. CCL23 production was increased in human neutrophils that infiltrated mouse brains compared to those in the peripheral circulation. It is known that an early intense inflammatory response (within hours) is associated with poor outcomes after CA. Our data indicate that late activation of neutrophils in brain tissue may also promote ongoing injury via the production of CCL23 and impair recovery after cardiac arrest.


Assuntos
Parada Cardíaca , Humanos , Camundongos , Animais , Parada Cardíaca/complicações , Quimiocinas , Quimiocinas CC
2.
Cancers (Basel) ; 15(21)2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37958399

RESUMO

Ewing sarcoma (ES) is one of the most frequent types of malignant tumors among children. The active metabolic state of ES cells presents a new potential target for therapeutic interventions. As a primary regulator of cellular homeostasis, carbonic anhydrases (CAs; EC 4.2.1.1) have emerged as promising molecular targets for the development of anticancer drugs. Within the present study, we tested the commercial drug acetazolamide and our previously discovered inhibitors to target the CAII isoform, which was overexpressed and positively correlated with ES patient relapse. We employed molecular biology tests to identify effective inhibitors of CAII that can induce ferroptosis by downregulating FTH1 expression in ES cells. In vitro, we have also demonstrated their ability to reduce cell proliferation, decrease invasion, and induce apoptosis- or autophagy-related cell death. Using Western blotting, we confirmed the induction of cathepsin B in cells treated with CA inhibitors. It was found that the suppression of cathepsin B expression during the treatment reduces the anticancer efficacy of selected CAII inhibitors. These experiments highlighted profound antitumor activity of CAII inhibitors attributive to their remarkable ability to trigger ferroptosis in Ewing sarcoma cells without causing substantial host damage. The obtained results suggest that cytosolic CAII may be a prospective target for ES treatment, and CAII inhibitors can be considered as potential single-agent or combination antitumor agents to be used in the treatment of ES.

3.
Cancer Gene Ther ; 30(8): 1066-1071, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37037906

RESUMO

Ewing sarcoma (ES) is an aggressive malignant tumor, characterized by non-random chromosomal translocations that produce fusion genes. Fusion genes and fusion protein products are promising targets for gene therapy. Therapeutic approaches and strategies vary based on target molecules (nucleotides, proteins) of interest. We present an extensive literature review of active molecules for gene therapy and methods of gene therapy delivery, both of which are necessary for successful treatment.


Assuntos
Neoplasias Ósseas , Sarcoma de Ewing , Humanos , Sarcoma de Ewing/genética , Sarcoma de Ewing/terapia , Sarcoma de Ewing/patologia , Neoplasias Ósseas/terapia , Proteínas , Terapia Genética , Proteínas de Fusão Oncogênica/genética
4.
Biomedicines ; 10(5)2022 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-35625723

RESUMO

Multiple efforts are currently underway to develop targeted therapeutic deliveries to the site of glioblastoma progression. The use of carriers represents advancement in the delivery of various therapeutic agents as a new approach in neuro-oncology. Mesenchymal stem cells (MSCs) and neural stem cells (NSCs) are used because of their capability in migrating and delivering therapeutic payloads to tumors. Two of the main properties that carrier cells should possess are their ability to specifically migrate from the bloodstream and low immunogenicity. In this article, we also compared the morphological and molecular features of each type of stem cell that underlie their migration capacity to glioblastoma. Thus, the major focus of the current review is on proteins and lipid molecules that are released by GBM to attract stem cells.

5.
Cell Signal ; 96: 110360, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35609807

RESUMO

We investigated the cell surface expression of ErbB receptors on left ventricular (LV) epicardial endothelial cells and CD105+ cells obtained from cardiac biopsies of patients undergoing coronary artery bypass grafting surgery (CABG). Endothelial cells and CD105+ non-endothelial cells were freshly isolated from LV epicardial biopsies obtained from 15 subjects with diabetes mellitus (DM) and 8 controls. The expression of ErbB receptors was examined using flow cytometry. We found that diabetes mellitus (DM) and high levels of hemoglobin A1C are associated with reduced expression of ErbB2. To determine if the expression of ErbB2 receptors is regulated by glucose levels, we examined the effect of high Glucose in human microvascular endothelial cells (HMEC-1) and CD105+ non-endothelial cells, using a novel flow cytometric approach to simultaneously determine the total level, cell surface expression, and phosphorylation of ErbB2. Incubation of cells in the presence of 25 mM d-glucose resulted in decreased cell surface but not total levels of ErbB2. The level of ErbB2 at the cell surface is controlled by disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) that is expressed on LV epicardial cells. Inhibition of ADAM10 prevented the high glucose-dependent decrease in the cell surface expression of ErbB2. We suggest that high Glucose depresses ErbB receptor signaling in endothelial cells and cardiac progenitor cells via the promotion of ADAM10-dependent cleavage of ErbB2 at the cell surface, thus contributing to vascular dysfunction and adverse remodeling seen in diabetic patients.


Assuntos
Diabetes Mellitus , Células Endoteliais , Células Endoteliais/metabolismo , Glucose , Ventrículos do Coração/metabolismo , Humanos , Fosforilação , Receptor ErbB-2/metabolismo , Transdução de Sinais
6.
Cancers (Basel) ; 14(8)2022 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-35454895

RESUMO

Ewing sarcoma (ES) is an uncommon cancer that arises in mesenchymal tissues and represents the second most widespread malignant bone neoplasm after osteosarcoma in children. Amplifications in genomic, proteomic, and metabolism are characteristics of sarcoma, and targeting altered cancer cell molecular processes has been proposed as the latest promising strategy to fight cancer. Recent technological advancements have elucidated some of the underlying oncogenic characteristics of Ewing sarcoma. Offering new insights into the physiological basis for this phenomenon, our current review examines the dynamics of ES signaling as it related to both ES and the microenvironment by integrating genomic and proteomic analyses. An extensive survey of the literature was performed to compile the findings. We have also highlighted recent and ongoing studies integrating metabolomics and genomics aimed at better understanding the complex interactions as to how ES adapts to changing biochemical changes within the tumor microenvironment.

7.
J Cardiovasc Pharmacol Ther ; 26(6): 562-574, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34264787

RESUMO

While ischemia itself can kill heart muscle, much of the infarction after a transient period of coronary artery occlusion has been found to result from injury during reperfusion. Here we review the role of inflammation and possible pyroptosis in myocardial reperfusion injury. Current evidence suggests pyroptosis's contribution to infarction may be considerable. Pyroptosis occurs when inflammasomes activate caspases that in turn cleave off an N-terminal fragment of gasdermin D. This active fragment makes large pores in the cell membrane thus killing the cell. Inhibition of inflammation enhances cardiac tolerance to ischemia and reperfusion injury. Stimulation of the purinergic P2X7 receptor and the ß-adrenergic receptor and activation of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) by toll-like receptor (TLR) agonists are all known to contribute to ischemia/reperfusion (I/R) cardiac injury through inflammation, potentially by pyroptosis. In contrast, stimulation of the cannabinoid CB2 receptor reduces I/R cardiac injury and inhibits this pathway. MicroRNAs, Akt, the phosphate and tension homology deleted on chromosome 10 protein (PTEN), pyruvate dehydrogenase and sirtuin-1 reportedly modulate inflammation in cardiomyocytes during I/R. Cryopyrin and caspase-1/4 inhibitors are reported to increase cardiac tolerance to ischemic and reperfusion cardiac injury, presumably by suppressing inflammasome-dependent inflammation. The ambiguity surrounding the role of pyroptosis in reperfusion injury arises because caspase-1 also activates cytotoxic interleukins and proteolytically degrades a surprisingly large number of cytosolic enzymes in addition to activating gasdermin D.


Assuntos
Isquemia Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Piroptose , Animais , Inibidores de Caspase/farmacologia , Humanos , Isquemia Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Proteína 3 que Contém Domínio de Pirina da Família NLR , Proteínas de Ligação a Fosfato , Proteínas Citotóxicas Formadoras de Poros , Ratos
8.
Eur J Pharmacol ; 907: 174302, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34217713

RESUMO

Coronary artery occlusion (45 min) and reperfusion (2 h) was performed in rats anesthetized with α-chloralose. Opioid receptor agonists were administered intravenously 5 min before reperfusion, while opioid receptor antagonists were administered 10 min before reperfusion. The non-selective opioid δ-receptor agonist DADLE at a dose of 0.088 mg/kg had no effect the infarct size/area at risk ratio. The selective opioid δ-receptor agonist BW373 was administered at a dose of 1 mg/kg. This opioid at a dose of 1 mg/kg reduced infarct size. The selective opioid δ1-receptor agonist DPDPE at a dose of 0.1 mg/kg and 0.969 mg/kg did not affect infarct size. The selective opioid δ2-receptor agonist deltorphin II at a dose of 0.12 mg/kg reduced infarct size by one half. The opioid δ-receptor agonist p-Cl-Phe-DPDPE was administered at a dose of 0.105 mg/kg and 1.02 mg/kg. This opioid at a dose of 1.02 mg/kg reduced infarct size. The universal opioid receptor antagonists, naltrexone and naloxone methiodide acting on peripheral opioid receptor, as well as the selective opioid δ-receptor antagonist TIIP[ψ], the selective opioid δ2-receptor antagonist naltriben eliminated the infarct limiting effect of deltorphin II. The selective opioid κ receptor antagonist nor-binaltorphimine, the selective opioid µ receptor antagonist CTAP, and the selective opioid δ1-receptor antagonist BNTX did not abolish the protective effect of deltorphin II. Deltorphin II exhibited the most pronounced cardioprotective effect during reperfusion. These studies clearly indicate that the activation of opioid δ2-receptor located in cardiomyocytes increases the resistance of the heart to reperfusion injury.


Assuntos
Receptores Opioides delta , Animais , Antagonistas de Entorpecentes , Ratos , Receptores Opioides mu
9.
Curr Cardiol Rev ; 17(4): e230421186874, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33059566

RESUMO

There is considerable evidence that autophagy in cardiomyocytes is activated by hypoxia/ reoxygenation (H/R) or in hearts by ischemia/reperfusion (I/R). Depending upon the experimental model and duration of ischemia, increases in autophagy in this setting maybe beneficial (cardioprotective) or deleterious (exacerbate I/R injury). Besides the conundrum as to whether or not autophagy is an adaptive process, it is clearly regulated by a number of diverse molecules, including reactive oxygen species (ROS), various kinases, hydrogen sulfide (H2S) and nitric oxide (NO). The purpose of this review was to address briefly the controversy regarding the role of autophagy in this setting and to examine a variety of disparate molecules that are involved in its regulation.


Assuntos
Traumatismo por Reperfusão , Autofagia , Humanos , Sulfeto de Hidrogênio , Isquemia , Miócitos Cardíacos , Óxido Nítrico , Espécies Reativas de Oxigênio
10.
J Cardiovasc Pharmacol Ther ; 26(2): 131-148, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32840121

RESUMO

In the past 10 years, mortality from acute myocardial infarction has not decreased despite the widespread introduction of percutaneous coronary intervention. The reason for this situation is the absence in clinical practice of drugs capable of preventing reperfusion injury of the heart with high efficiency. In this regard, noteworthy natriuretic peptides (NPs) which have the infarct-limiting effect, prevent reperfusion cardiac injury, prevent adverse post-infarction remodeling of the heart. Atrial natriuretic peptide does not have the infarct-reducing effect in rats with alloxan-induced diabetes mellitus. NPs have the anti-apoptotic and anti-inflammatory effects. There is indirect evidence that NPs inhibit pyroptosis and autophagy. Published data indicate that NPs inhibit reactive oxygen species production in cardiomyocytes, aorta, heart, kidney and the endothelial cells. NPs can suppress aldosterone, angiotensin II, endothelin-1 synthesize and secretion. NPs inhibit the effects aldosterone, angiotensin II on the post-receptor level through intracellular signaling events. NPs activate guanylyl cyclase, protein kinase G and protein kinase A, and reduce phosphodiesterase 3 activity. NO-synthase and soluble guanylyl cyclase are involved in the cardioprotective effect of NPs. The cardioprotective effect of natriuretic peptides is mediated via activation of kinases (AMPK, PKC, PI3 K, ERK1/2, p70s6 k, Akt) and inhibition of glycogen synthase kinase 3ß. The cardioprotective effect of NPs is mediated via sarcolemmal KATP channel and mitochondrial KATP channel opening. The cardioprotective effect of brain natriuretic peptide is mediated via MPT pore closing. The anti-fibrotic effect of NPs may be mediated through inhibition TGF-ß1 expression. Natriuretic peptides can inhibit NF-κB activity and activate GATA. Hemeoxygenase-1 and peroxisome proliferator-activated receptor γ may be involved in the infarct-reducing effect of NPs. NPs exhibit the infarct-limiting effect in patients with acute myocardial infarction. NPs prevent post-infarction remodeling of the heart. To finally resolve the question of the feasibility of using NPs in AMI, a multicenter, randomized, blind, placebo-controlled study is needed to assess the effect of NPs on the mortality of patients after AMI.


Assuntos
Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Peptídeos Natriuréticos/farmacologia , Animais , Fator Natriurético Atrial , Modelos Animais de Doenças , Humanos , Isquemia , Canais KATP/metabolismo , Camundongos , Peptídeos Natriuréticos/metabolismo , Proteínas Quinases/metabolismo , Ratos
11.
Hormones (Athens) ; 19(3): 329-339, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32399937

RESUMO

The thyroid gland plays a crucial role in the regulation of metabolism, oxygen consumption, and the release of energy in the form of heat to maintain the body. Even at rest, these processes are sensitive to changes in thyroid function. This means that along with the adrenergic system, thyroid function determines the organism's ability to adapt to cold. Cold adaptation causes deiodination of thyroxine (T4) and thus promotes an increase in blood triiodothyronine (T3) levels in humans and animals. Triiodothyronine is an inductor of iodothyronine deiodinase expression in brown fat, liver, and kidney. Iodothyronine deiodinase plays an important role in adaptation of the organism to cold by contributing to high adrenergic reactivity of brown fat. T3 also leads to an increase in expression of uncoupling proteins and uncoupling oxidative phosphorylation and an increase in heat production. The aim of this article is to review the available literature regarding the role of thyroid hormones in adaptation to cold and to present the current knowledge of the understanding of the molecular mechanism underlying their action during cold adaptation.


Assuntos
Adaptação Fisiológica/fisiologia , Tecido Adiposo Marrom/metabolismo , Temperatura Baixa , Termogênese/fisiologia , Hormônios Tireóideos/metabolismo , Animais , Humanos
12.
Gen Physiol Biophys ; 38(3): 245-251, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31184311

RESUMO

We have established that the continuous cold exposure (CCE, 4°C, 4 weeks) causes cold adaptation, increases systolic blood pressure, exerts infarct-limiting effect during coronary artery occlusion (45 min) and reperfusion (2 h). The CCE increases adrenal weight, heart weight and triiodothyronine (T3) level but does not change thymus, spleen weight, serum cortisol, corticosterone and thyroxin (T4) levels. The long-term (4°C, 8 h/day, 4 weeks) intermittent cold exposure (LICE) induces adaptation to the cold and increases T4 level. The brief (4°C, 1.5 h/day, 4 weeks) intermittent cold exposure (BICE) also evokes adaptation to the cold but had no effect on the blood pressure, the cardiac tolerance to ischemia/reperfusion, and does not change thymus, spleen weight, serum cortisol, corticosterone, T3 and T4 levels.


Assuntos
Aclimatação/fisiologia , Temperatura Baixa , Glucocorticoides/sangue , Traumatismo por Reperfusão/prevenção & controle , Hormônios Tireóideos/sangue
13.
J Cardiovasc Pharmacol Ther ; 24(5): 403-421, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31035796

RESUMO

A humoral mechanism of cardioprotection by remote ischemic preconditioning (RIP) has been clearly demonstrated in various models of ischemia-reperfusion including upper and lower extremities, liver, and the mesenteric and renal arteries. A wide range of humoral factors for RIP have been proposed including hydrophobic peptides, opioid peptides, adenosine, prostanoids, endovanilloids, endocannabinoids, calcitonin gene-related peptide, leukotrienes, noradrenaline, adrenomedullin, erythropoietin, apolipoprotein, A-I glucagon-like peptide-1, interleukin 10, stromal cell-derived factor 1, and microRNAs. Virtually, all of the components of ischemic preconditioning's signaling pathway such as nitric oxide synthase, protein kinase C, redox signaling, PI3-kinase/Akt, glycogen synthase kinase ß, ERK1/2, mitoKATP channels, Connexin 43, and STAT were all found to play a role. The signaling pattern also depends on which remote vascular bed was subjected to ischemia and on the time between applying the rip and myocardial ischemia occurs. Because there is convincing evidence for many seemingly diverse humoral components in RIP, the most likely explanation is that the overall mechanism is complex like that seen in ischemic preconditioning where multiple components are both in series and in parallel and interact with each other. Inhibition of any single component in the right circumstance may block the resulting protective effect, and selectively activating that component may trigger the protection. Identifying the humoral factors responsible for RIP might be useful in developing drugs that confer RIP's protection in a more comfortable and reliable manner.


Assuntos
Precondicionamento Isquêmico , Infarto do Miocárdio/prevenção & controle , Miocárdio/metabolismo , Traumatismo por Reperfusão/prevenção & controle , Transdução de Sinais , Animais , Humanos , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Miocárdio/patologia , Fluxo Sanguíneo Regional , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Resultado do Tratamento
14.
Curr Cardiol Rev ; 15(3): 177-187, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30813880

RESUMO

The hypothetical trigger of remote postconditioning (RPost) of the heart is the highmolecular weight hydrophobic peptide(s). Nitric oxide and adenosine serve as intermediaries between the peptide and intracellular structures. The role of the autonomic nervous system in RPost requires further study. In signaling mechanism RPost, kinases are involved: protein kinase C, PI3, Akt, JAK. The hypothetical end effector of RPost is aldehyde dehydrogenase-2, the transcription factors STAT, Nrf2, and also the BKCa channel.


Assuntos
Coração/fisiopatologia , Isquemia/fisiopatologia , Pós-Condicionamento Isquêmico/métodos , Miocárdio/metabolismo , Feminino , Humanos , Masculino , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/patologia , Transdução de Sinais
15.
Gen Physiol Biophys ; 37(5): 537-547, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30307404

RESUMO

It was established that adaptation to chronic continuous normobaric hypoxia (CCNH) increases cardiac tolerance to ischemia and reperfusion. It was performed coronary artery occlusion (20 min) and reperfusion (3 h) in Wistar rats. CCNH promoted a decrease in the infarct size/area at risk ratio in 2-fold. CCNH promoted an increase in the nitrite/nitrate levels in blood serum and myocardium. Pretreatment with protein kinase C (PKC) inhibitor chelerythrine, NO-synthase (NOS) inhibitor L-NAME, iNOS inhibitor S-methylisothiourea, KATP channel blocker glibenclamide, mitoKATP channel blocker 5-hydroxydecanoic acid abolished the infarct-reducing effect of CCNH. The non-selective tyrosine kinase inhibitor genistein attenuated but not eliminated infarct-sparing effect of CCNH. The nNOS inhibitor 7-nitroindazole, sarcKATP channel blocker HMR 1098, MPT pore inhibitor atractyloside, PI3 kinase inhibitor wortmannin did not reverse infarct-limiting effect of CCNH. It was concluded that infarct-reducing effect of CCNH is mediated via PKC, iNOS activation and mitoKATP channel opening. While nNOS, PI3 kinase, sarcKATP channel, MPT pore are not involved in the development of CCNH-induced cardiac tolerance to impact of ischemia-reperfusion.


Assuntos
Canais KATP/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Miocárdio/citologia , Óxido Nítrico Sintase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteína Quinase C/metabolismo , Proteínas Tirosina Quinases/metabolismo , Animais , Arritmias Cardíacas/patologia , Hipóxia Celular , Hemodinâmica , Masculino , Poro de Transição de Permeabilidade Mitocondrial , Infarto do Miocárdio/patologia , Miocárdio/patologia , Nitratos/sangue , Nitritos/sangue , Ratos , Ratos Wistar , Transdução de Sinais
16.
Clin Exp Pharmacol Physiol ; 42(5): 496-501, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25739423

RESUMO

Chronic continuous normobaric hypoxia (CNH) increases cardiac tolerance to acute ischaemia/reperfusion injury. The objective of this study was to find out whether the cardioprotective effect of CNH mediated by opioid receptors is associated with preservation of mitochondrial function. Rats were adapted to CNH (12% oxygen) for 3 weeks. Isolated perfused hearts were subjected to 45 min of global ischaemia and 30 min of reperfusion; subgroups were pretreated with non-selective opioid receptor antagonist naloxone (300 nmol/L) for 10 min. Cardiac contractile function, creatine kinase activity in coronary effluent, mitochondrial respiration rate, and calcium retention capacity were assessed. Adaptation to CNH decreased myocardial creatine kinase release during reperfusion and improved the post-ischaemic recovery of contractile function, mitochondrial state 3 and uncoupled respiration rates, and calcium retention capacity compared to the normoxic group. These protective effects were completely abolished by naloxone. The contractile recovery positively correlated with state 3 respiration and calcium retention capacity. The results suggest that the preserved mitochondrial function contributes to the protected cardiac phenotype afforded by adaptation to CNH and point to an important role of opioid receptor activation.


Assuntos
Hipóxia/patologia , Mitocôndrias Cardíacas/patologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Receptores Opioides/metabolismo , Adaptação Fisiológica , Animais , Respiração Celular , Masculino , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Ratos , Ratos Wistar , Fatores de Tempo
17.
Life Sci ; 93(9-11): 373-9, 2013 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-23891777

RESUMO

AIMS: The objective of this study was to examine the involvement of endogenous opioid peptides and opioid receptor (OR) subtypes in the cardioprotective effect of adaptation to chronic hypoxia in rats. MAIN METHODS: Rats were exposed to continuous normobaric hypoxia (CNH; 12% oxygen) for 3 weeks. Myocardial ischemia was induced by 20-min coronary artery occlusion followed by 3-h reperfusion in anesthetized open-chest animals. Various OR antagonists were administered to rats prior to ischemia. The size of myocardial infarction and the incidence of ischemic ventricular arrhythmias were assessed. Myocardial and plasma concentrations of opioid peptides (met-enkephalin, ß-endorphin, and endomorphins) were determined. KEY FINDINGS: Adaptation to CNH significantly increased myocardial and plasma concentrations of opioids, potentiated their further elevation by ischemia/reperfusion, and reduced myocardial infarct size, but it did not affect the incidence of ischemic arrhythmias. The infarct size-limiting effect of CNH was abolished by OR antagonists naltrexone (non-selective), naloxone methiodide (non-selective peripherally acting), TIPP[ψ] (δ-OR), naltriben (δ2-OR), or CTAP (µ-OR), while BNTX (δ1-OR) and nor-binaltorphimine (κ-OR) had no effect. SIGNIFICANCE: The results suggest that the infarct size-limiting effect afforded by adaptation to CNH is mediated by activation of peripheral δ2- and µ-ORs by elevated levels of endogenous opioid peptides.


Assuntos
Arritmias Cardíacas/fisiopatologia , Infarto do Miocárdio/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Adaptação Fisiológica , Animais , Arritmias Cardíacas/etiologia , Encefalina Metionina/metabolismo , Hipóxia/complicações , Masculino , Infarto do Miocárdio/etiologia , Antagonistas de Entorpecentes/farmacologia , Oligopeptídeos/sangue , Oligopeptídeos/metabolismo , Ratos , Ratos Wistar , Receptores Opioides delta/metabolismo , Receptores Opioides mu/metabolismo , beta-Endorfina/metabolismo
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