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ischemia reperfusion model .DADLE might have a protective effect on lung tissues of ALI in rats .
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PURPOSE: Oxygen is indispensable for survival and aerobic metabolism in all mammalian cells. Inadequate oxygen triggers a multifaceted cellular response negatively impacting important physiological functions which are observed in clinical diseases such as stroke, drowning, cardiac arrest, hazardous gas poisoning, myocardial infarction and vascular dementia. In this study, we investigated the neuroprotective effect of a synthetic delta-opioid agonist, [D-Ala2, D-Leu5] enkephalin (DADLE), and its role in ischemic neuronal injury. METHODS: This experiment was conducted in vitro using a primary culture of rat cortical neurons. Ischemia induction was performed using a hypoxic chamber. To test the degree of neuronal viability, as protected by delta-opioid stimulation with DADLE under ischemia, we used three independent approaches including a lactate dehydrogenase assay, MTT assay, and an immunofluorescent staining assay for viable cells. In addition, the gene expressions of caspase-3 and heat shock protein 70 were analyzed using real-time PCR. RESULTS: Incubation of the cortical neurons with DADLE protected them from ischemia-induced cytotoxicity, as observed by all three independent viability assays. Also, we found that its neuroprotective effect might be related with suppression of the caspase-3 gene. CONCLUSION: The results of this study suggested that DADLE exhibits a neuroprotective effect against ischemia-induced neuronal cell death.
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Animais , Ratos , Caspase 3 , Morte Celular , Demência Vascular , Afogamento , Leucina Encefalina-2-Alanina , Encefalinas , Intoxicação por Gás , Expressão Gênica , Parada Cardíaca , Proteínas de Choque Térmico HSP70 , Isquemia , L-Lactato Desidrogenase , Infarto do Miocárdio , Neurônios , Fármacos Neuroprotetores , Oxigênio , Acidente Vascular CerebralRESUMO
PURPOSE: Oxygen is indispensable for survival and aerobic metabolism in all mammalian cells. Inadequate oxygen triggers a multifaceted cellular response negatively impacting important physiological functions which are observed in clinical diseases such as stroke, drowning, cardiac arrest, hazardous gas poisoning, myocardial infarction and vascular dementia. In this study, we investigated the neuroprotective effect of a synthetic delta-opioid agonist, [D-Ala2, D-Leu5] enkephalin (DADLE), and its role in ischemic neuronal injury. METHODS: This experiment was conducted in vitro using a primary culture of rat cortical neurons. Ischemia induction was performed using a hypoxic chamber. To test the degree of neuronal viability, as protected by delta-opioid stimulation with DADLE under ischemia, we used three independent approaches including a lactate dehydrogenase assay, MTT assay, and an immunofluorescent staining assay for viable cells. In addition, the gene expressions of caspase-3 and heat shock protein 70 were analyzed using real-time PCR. RESULTS: Incubation of the cortical neurons with DADLE protected them from ischemia-induced cytotoxicity, as observed by all three independent viability assays. Also, we found that its neuroprotective effect might be related with suppression of the caspase-3 gene. CONCLUSION: The results of this study suggested that DADLE exhibits a neuroprotective effect against ischemia-induced neuronal cell death.
Assuntos
Animais , Ratos , Caspase 3 , Morte Celular , Demência Vascular , Afogamento , Leucina Encefalina-2-Alanina , Encefalinas , Intoxicação por Gás , Expressão Gênica , Parada Cardíaca , Proteínas de Choque Térmico HSP70 , Isquemia , L-Lactato Desidrogenase , Infarto do Miocárdio , Neurônios , Fármacos Neuroprotetores , Oxigênio , Acidente Vascular CerebralRESUMO
Objective To study the protective effects of DADLE on pulmonary function in rats with sepsis and the mechanism.Methods Seventy-two SD rats were randomly divided into sham operated group(SO),septic group(SEP),and DADLEtreated group (DADLE).Sepsis model was induced by cecal ligation and puncture(CLP).In SO group,the abdomen was opened without any other treatment.In DADLE-treated group,DADLE(0.5 mg/ml) was administerd at a dose of 5 ml/kg by intravenous injection after CLP.Rats were sacrificed at the 2nd,6th and 10th h after CLP.Arterial blood was collected for blood gas analysis.The wet-to-dry lung weight ratio was measured,and the levels of TNF-a and IL-6 in blood were detected.The levels of MPO,MDA and ATP in lung tissue were determined.The pathologic changes of the lungs were examined under a light microscope.Results As compared with SEP group,PaCO_2,and PaO_2 were significantly increased(P<0.05),while the wet-to-dry ratio and levels of serum TNF-a and IL-6 were significantly reduced(P<0.05),and levels of MPO and MDA were significantly reduced(P<0.05) and content of ATP in lung tissue was significantly increased (P<0.05)in DADLE group.More severe pathological changes were found in SEP group than in DADLE group.Conclusion DADLE has pulmonary protective effects in rats with sepsis.
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This study was undertaken to investigate the effects of [D-Ala2, D-Leu5]-enkephalin (DADLE) on the spontaneous activity of medial vestibular nuclear neurons of the rat. Sprague-Dawley rats, aged 14 to 16 days, were anesthetized with ether and decapitated. After enzymatic digestion, the brain stem portion of medial vestibular nuclear neuron was obtained by micropunching. The dissociated neurons were transferred to a recording chamber mounted on an inverted microscope, and spontaneous action potentials were recorded by standard patch-clamp techniques. The spontaneous action potentials were increased by DADLE in 12 cells and decreased in 3 cells. The spike frequency and resting membrane potential of these cells were increased by DADLE. The depth of afterhyperpolarization was not affected by DADLE. The potassium currents were decreased in 20 cells and increased in 5 cells. These results suggest that DADLE increases the neuronal activity of the medial vestibular nuclear neurons by altering resting membrane potential.