RESUMO
El precondicionamiento isquémico remoto es una manera eficaz de disminuir el daño por isquemia y reperfusión en el corazón y otros órganos como cerebro o riñón, en modelos experimentales. Este consiste en realizar entre 3 y 5 ciclos de 5 minutos de isquemia seguidos del mismo tiempo de reperfusión, en un tejido alejado del que se quiere proteger, normalmente una extremidad. Estudios preclínicos en animales indican que la isquemia precondicionante inicia señales nerviosas y humorales en el tejido isquémico remoto, que en el corazón activan mecanismos de protección. La señal nerviosa se origina en fibras sensoriales que a nivel cerebral producen una activación del sistema parasimpático. El nervio vago activa ganglios cardíacos intrínsecos del corazón lo que induce protección. Además, desde el tejido isquémico se liberan a la circulación diferentes mediadores que viajan en forma libre o en vesículas lipídicas (exosomas) que inician vías de señalización protectoras en el corazón. A pesar del éxito del precondicionamiento isquémico remoto en animales de experimentación, su aplicación en seres humanos no ha tenido resultados claros. Esta discrepancia puede deberse a una diversidad de factores tales como la edad, la existencia de otras patologías, uso de fármacos u otros tratamientos que afectan la respuesta de los pacientes. Se requiere un mayor conocimiento de las bases moleculares de este mecanismo de protección para que su aplicación en clínica sea exitosa.
In experimental models, remote ischemic preconditioning effectively decreases ischemia reperfusion injury to the heart and other organs such as the brain or kidney. It consists of 3 to 5 cycles of 5 minutes of ischemia followed by 5 minutes of reperfusion, in a remote tissue, usually a limb. Preclinical studies in animals indicate that preconditioning ischemia initiates neural and humoral signals in the remote ischemic tissue, which activate protective mechanisms in the heart. The nervous signal originates in sensory fibers that activate the parasympathetic system in the brain. The vagus nerve activates the intrinsic cardiac ganglia of the heart, leading to protection from ischemic injury. Furthermore, mediators are released from the ischemic tissue into the circulation that travels freely or in lipid vesicles (exosomes) to the heart where they initiate protective signaling pathways. Despite the success of remote ischemic preconditioning in experimental animals, its application in humans has not produced clear results. This discrepancy may be due to a variety of factors such as age, the existence of other pathologic processes, or the use of drugs or other treatments that affect the patient´s response. An increased knowledge of the molecular bases of this protective mechanism is required for its clinical application to be successful.
Assuntos
Humanos , Traumatismo por Reperfusão/terapia , Precondicionamento Isquêmico/métodos , Precondicionamento Isquêmico Miocárdico/métodosRESUMO
PURPOSE: Remote ischemic preconditioning (RIPC) confers cardioprotection against ischemia reperfusion (IR) injury. However, the precise mechanisms involved in RIPC-induced cardioprotection are not fully explored. The present study was aimed to identify the role of melatonin in RIPC-induced late cardioprotective effects in rats and to explore the role of H2S, TNF-α and mitoKATP in melatonin-mediated effects in RIPC. METHODS: Wistar rats were subjected to RIPC in which hind limb was subjected to four alternate cycles of ischemia and reperfusion of 5 min duration by using a neonatal blood pressure cuff. After 24 h of RIPC or ramelteon-induced pharmacological preconditioning, hearts were isolated and subjected to IR injury on the Langendorff apparatus. RESULTS: RIPC and ramelteon preconditioning protected the hearts from IR injury and it was assessed by a decrease in LDH-1, cTnT and increase in left ventricular developed pressure (LVDP). RIPC increased the melatonin levels (in plasma), H2S (in heart) and decreased TNF-α levels. The effects of RIPC were abolished in the presence of melatonin receptor blocker (luzindole), ganglionic blocker (hexamethonium) and mitochondrial KATP blocker (5-hydroxydecanoic acid). CONCLUSIONS: RIPC produce delayed cardioprotection against IR injury through the activation of neuronal pathway, which may increase the plasma melatonin levels to activate the cardioprotective signaling pathway involving the opening of mitochondrial KATP channels, decrease in TNF-α production and increase in H2S levels. Ramelteon-induced pharmacological preconditioning may also activate the cardioprotective signaling pathway involving the opening of mitochondrial KATP channels, decrease in TNF-α production and increase in H2S levels.
Assuntos
Precondicionamento Isquêmico Miocárdico , Precondicionamento Isquêmico , Melatonina , Infarto do Miocárdio , Traumatismo por Reperfusão Miocárdica , Ratos , Animais , Infarto do Miocárdio/metabolismo , Melatonina/farmacologia , Traumatismo por Reperfusão Miocárdica/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Ratos Wistar , Transdução de Sinais , Isquemia , Canais KATP/metabolismo , Canais KATP/farmacologiaRESUMO
Ischemic preconditioning (IP) is an innate phenomenon, triggered by brief, non-lethal cycles of ischemia/reperfusion applied to a tissue or organ that confers tolerance to a subsequent more prolonged ischemic event. Once started, it can reduce the severity of myocardial ischemia associated with some clinical situations, such as percutaneous coronary intervention (PCI) and intermittent aortic clamping during coronary artery bypass graft surgery (CABG). Although the mechanisms underlying IP have not been completely elucidated, several studies have shown that this phenomenon involves the participation of cell triggers, intracellular signaling pathways, and end-effectors. Understanding this mechanism enables the development of preconditioning mimetic agents. It is known that a range of medications that activate the signaling cascades at different cellular levels can interfere with both the stimulation and the blockade of IP. Investigations of signaling pathways underlying ischemic conditioning have identified a number of therapeutic targets for pharmacological manipulation. This review aims to present and discuss the effects of several medications on myocardial IP.
Assuntos
Precondicionamento Isquêmico Miocárdico , Isquemia Miocárdica , Intervenção Coronária Percutânea , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Coração , IsquemiaRESUMO
PURPOSE: The present study explored the influence of liraglutide on remote preconditioning-mediated cardioprotection in diabetes mellitus along with the role of nuclear factor erythroid 2-related factor 2 (Nrf2), hypoxia inducible factor (HIF-1α) and hydrogen sulfide (H2S). METHODS: Streptozotocin was given to rats to induce diabetes mellitus and rats were kept for eight weeks. Four cycles of ischemia and reperfusion were given to hind limb to induce remote preconditioning. After 24 h, hearts were isolated and subjected to 30 min of ischemia and 120 min of reperfusion on Langendorff system. Liraglutide was administered along with remote preconditioning. Cardiac injury was assessed by measuring the release of creatine kinase (CK-MB), cardiac troponin (cTnT) and development of left ventricular developed pressure. After ischemia-reperfusion, hearts were homogenized to measure the nuclear cytoplasmic ratio of Nrf2, H2S and HIF-1α levels. RESULTS: In diabetic rats, there was more pronounced injury and the cardioprotective effects of remote preconditioning were not observed. Administration of liraglutide restored the cardioprotective effects of remote preconditioning in a dose-dependent manner. Moreover, liraglutide increased the Nrf2, H2S and HIF-1α levels in remote preconditioning-subjected diabetic rats. CONCLUSIONS: Liraglutide restores the lost cardioprotective effects of remote preconditioning in diabetes by increasing the expression of Nrf2, H2S and HIF-1α.
Assuntos
Diabetes Mellitus Experimental , Sulfeto de Hidrogênio , Precondicionamento Isquêmico Miocárdico , Precondicionamento Isquêmico , Infarto do Miocárdio , Traumatismo por Reperfusão Miocárdica , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Sulfeto de Hidrogênio/farmacologia , Liraglutida/farmacologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Fator 2 Relacionado a NF-E2 , Ratos , Ratos Wistar , Transdução de SinaisRESUMO
Since the discovery of ischemic pre- and post-conditioning, more than 30 years ago, the knowledge about the mechanisms and signaling pathways involved in these processes has significantly increased. In clinical practice, on the other hand, such advancement has yet to be seen. This article provides an overview of ischemic pre-, post-, remote, and pharmacological conditioning related to the heart. In addition, we reviewed the cardioprotective signaling pathways and therapeutic agents involved in the above-mentioned processes, aiming to provide a comprehensive evaluation of the advancements in the field. The advancements made over the last decades cannot be ignored and with the exponential growth in techniques and applications. The future of pre- and post-conditioning is promising.
Assuntos
Pós-Condicionamento Isquêmico , Precondicionamento Isquêmico Miocárdico , Transdução de Sinais , Coração , HumanosRESUMO
ABSTRACT Purpose The present study explored the influence of liraglutide on remote preconditioning-mediated cardioprotection in diabetes mellitus along with the role of nuclear factor erythroid 2-related factor 2 (Nrf2), hypoxia inducible factor (HIF-1α) and hydrogen sulfide (H2S). Methods Streptozotocin was given to rats to induce diabetes mellitus and rats were kept for eight weeks. Four cycles of ischemia and reperfusion were given to hind limb to induce remote preconditioning. After 24 h, hearts were isolated and subjected to 30 min of ischemia and 120 min of reperfusion on Langendorff system. Liraglutide was administered along with remote preconditioning. Cardiac injury was assessed by measuring the release of creatine kinase (CK-MB), cardiac troponin (cTnT) and development of left ventricular developed pressure. After ischemia-reperfusion, hearts were homogenized to measure the nuclear cytoplasmic ratio of Nrf2, H2S and HIF-1α levels. Results In diabetic rats, there was more pronounced injury and the cardioprotective effects of remote preconditioning were not observed. Administration of liraglutide restored the cardioprotective effects of remote preconditioning in a dose-dependent manner. Moreover, liraglutide increased the Nrf2, H2S and HIF-1α levels in remote preconditioning-subjected diabetic rats. Conclusions Liraglutide restores the lost cardioprotective effects of remote preconditioning in diabetes by increasing the expression of Nrf2, H2S and HIF-1α.
Assuntos
Animais , Ratos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Precondicionamento Isquêmico Miocárdico , Diabetes Mellitus Experimental/tratamento farmacológico , Sulfeto de Hidrogênio , Sulfeto de Hidrogênio/farmacologia , Infarto do Miocárdio , Transdução de Sinais , Ratos Wistar , Fator 2 Relacionado a NF-E2 , Liraglutida/farmacologiaRESUMO
PURPOSE: The current study explored the involvement of neurogenic pathway-linked cholecystokinin (CCK) release in RIP-induced cardioprotection in rats. METHODS: Male Wistar rats were subjected to four cycles of alternate episodes of ischemia and reperfusion (five min each) to induce RIP. Thereafter, the hearts were subjected to global ischemia and reperfusion ex vivo. The myocardial damage was assessed by quantifying the levels of heartspecific biochemicals i.e. LDH-1, CK-MB and cTnT. Apoptotic cell injury was assessed by measuring the levels of caspase-3 and Bcl-2. The levels of CCK were measured in the plasma following RIP. RESULTS: Exposure to RIP significantly increased the plasma levels of CCK and attenuated IR-induced myocardial injury. Administration of CCK antagonist, proglumide significantly attenuated RIP-induced cardioprotection. Administration of hexamethonium, a ganglion blocker, abolished RIP-induced increase in plasma CCK levels and cardioprotective effects. Exogenous delivery of CCK-8 restored the effects of RIP in hexamethonium treated animals. CONCLUSION: RIP activates the neurogenic pathway that may increase the plasma levels of CCK, which may act on the heart-localized CCK receptors to produce cardioprotection against I/R injury.
Assuntos
Precondicionamento Isquêmico Miocárdico , Infarto do Miocárdio , Traumatismo por Reperfusão Miocárdica , Animais , Colecistocinina , Creatina Quinase , Membro Posterior , Masculino , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Ratos , Ratos WistarRESUMO
BACKGROUND: Anthracycline-induced cardiotoxicity (AIC), a condition associated with multiple mechanisms of damage, including oxidative stress, has been associated with poor clinical outcomes. Carvedilol, a ß-blocker with unique antioxidant properties, emerged as a strategy to prevent AIC, but recent trials question its effectiveness. Some evidence suggests that the antioxidant, not the ß-blocker effect, could prevent related cardiotoxicity. However, carvedilol's antioxidant effects are probably not enough to prevent cardiotoxicity manifestations in certain cases. We hypothesize that breast cancer patients taking carvedilol as well as a non-hypoxic myocardial preconditioning based on docosahexaenoic acid (DHA), an enhancer of cardiac endogenous antioxidant capacity, will develop less subclinical cardiotoxicity manifestations than patients randomized to double placebo. METHODS/DESIGN: We designed a pilot, randomized controlled, two-arm clinical trial with 32 patients to evaluate the effects of non-hypoxic cardiac preconditioning (DHA) plus carvedilol on subclinical cardiotoxicity in breast cancer patients undergoing anthracycline treatment. The trial includes four co-primary endpoints: changes in left ventricular ejection fraction (LVEF) determined by cardiac magnetic resonance (CMR); changes in global longitudinal strain (GLS) determined by two-dimensional echocardiography (ECHO); elevation in serum biomarkers (hs-cTnT and NT-ProBNP); and one electrocardiographic variable (QTc interval). Secondary endpoints include other imaging, biomarkers and the occurrence of major adverse cardiac events during follow-up. The enrollment and follow-up for clinical outcomes is ongoing. DISCUSSION: We expect a group of anthracycline-treated breast cancer patients exposed to carvedilol and non-hypoxic myocardial preconditioning with DHA to show less subclinical cardiotoxicity manifestations than a comparable group exposed to placebo. TRIAL REGISTRATION: ISRCTN registry, ID: ISRCTN69560410. Registered on 8 June 2016.
Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Antibióticos Antineoplásicos/efeitos adversos , Antioxidantes/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Carvedilol/uso terapêutico , Ácidos Docosa-Hexaenoicos/uso terapêutico , Doxorrubicina/efeitos adversos , Precondicionamento Isquêmico Miocárdico/métodos , Adolescente , Adulto , Idoso , Antibióticos Antineoplásicos/uso terapêutico , Biomarcadores/sangue , Neoplasias da Mama/sangue , Cardiotoxicidade/etiologia , Cardiotoxicidade/prevenção & controle , Método Duplo-Cego , Doxorrubicina/uso terapêutico , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Projetos Piloto , Volume Sistólico , Resultado do Tratamento , Função Ventricular Esquerda/efeitos dos fármacos , Adulto JovemRESUMO
Abstract Purpose: The current study explored the involvement of neurogenic pathway-linked cholecystokinin (CCK) release in RIP-induced cardioprotection in rats. Methods: Male Wistar rats were subjected to four cycles of alternate episodes of ischemia and reperfusion (five min each) to induce RIP. Thereafter, the hearts were subjected to global ischemia and reperfusion ex vivo. The myocardial damage was assessed by quantifying the levels of heartspecific biochemicals i.e. LDH-1, CK-MB and cTnT. Apoptotic cell injury was assessed by measuring the levels of caspase-3 and Bcl-2. The levels of CCK were measured in the plasma following RIP. Results: Exposure to RIP significantly increased the plasma levels of CCK and attenuated IR-induced myocardial injury. Administration of CCK antagonist, proglumide significantly attenuated RIP-induced cardioprotection. Administration of hexamethonium, a ganglion blocker, abolished RIP-induced increase in plasma CCK levels and cardioprotective effects. Exogenous delivery of CCK-8 restored the effects of RIP in hexamethonium treated animals. Conclusion: RIP activates the neurogenic pathway that may increase the plasma levels of CCK, which may act on the heart-localized CCK receptors to produce cardioprotection against I/R injury.
Assuntos
Animais , Masculino , Ratos , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Precondicionamento Isquêmico Miocárdico , Infarto do Miocárdio , Colecistocinina , Ratos Wistar , Creatina Quinase , Membro PosteriorRESUMO
BACKGROUND: Stress is defined as a complicated state that related to homeostasis disturbances, over-activity of the sympathetic nervous system and hypothalamus-pituitary-adrenal axis responses. Cardiac preconditioning reduces myocardial damages. OBJECTIVE: This study was designed to assess the cardioprotective effects of acute physical stress against ischemia/reperfusion (I/R) injury through the activation of the sympathetic nervous system. METHODS: Thirty-two male Wistar rats were divided into four groups; (1) IR (n = 8): rats underwent I/R, (2) Acute stress (St+IR) (n = 8): physical stress induced 1-hour before I/R, (3) Sympathectomy (Symp+IR) (n = 8): chemical sympathectomy was done 24-hours before I/R and (4) Sympathectomy- physical stress (Symp+St+IR) (n = 8): chemical sympathectomy induced before physical stress and I/R. Chemical sympathectomy was performed using 6-hydroxydopamine (100 mg/kg, sc). Then, the hearts isolated and located in the Langendorff apparatus to induce 30 minutes ischemia followed by 120 minutes reperfusion. The coronary flows, hemodynamic parameters, infarct size, corticosterone level in serum were investigated. P < 0.05 demonstrated significance. RESULTS: Physical stress prior to I/R could improve left ventricular developed pressure (LVDP) and rate product pressure (RPP) of the heart respectively, (63 ± 2 versus 42 ± 1.2, p < 0.05, 70 ± 2 versus 43 ± 2.6, p < 0.05) and reduces infarct size (22.16 ± 1.3 versus 32 ± 1.4, p < 0.05) when compared with the I/R alone. Chemical sympathectomy before physical stress eliminated the protective effect of physical stress on I/R-induced cardiac damages (RPP: 21 ± 6.6 versus 63 ± 2, p < 0.01) (LVDP: 38 ± 4.5 versus 43 ± 2.6, p < 0.01) (infarct size: 35 ± 3.1 versus 22.16 ± 1.3, p < 0.01). CONCLUSION: Findings indicate that acute physical stress can act as a preconditional stimulator and probably, the presence of sympathetic nervous system is necessary.