European journal of pharmacology
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This study investigated the effects of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one, MCI-186), a potent free radical scavenger, on the prevention of mitochondrial injury induced by hepatic ischemia and reperfusion. Mature male rats were subjected to 70 min of hepatic ischemia and 2 h of reperfusion. The rats received vehicle or edaravone (10 mg/kg body weight) intravenously prior to ischemia, before reperfusion and 1 h after reperfusion. ⋯ Mitochondrial lipid peroxidation was elevated in the vehicle-treated group, which was attenuated by edaravone, while mitochondrial glutathione peroxidase activity decreased in the vehicle-treated group, which was similarly abrogated by edaravone treatment. Electron microscopic observation demonstrated that treatment with edaravone restored the ischemia/reperfusion-induced disorganization of mitochondrial structures. Edaravone protects against mitochondrial injury, which prevents mitochondrial oxidative stress and improves ischemia/reperfusion-induced hepatic energy metabolism.
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Glucocorticoids are potent anti-inflammatory drugs. The molecular mechanisms underlying these effects have not yet been fully revealed. The aim of the present study was to establish whether methylprednisolone pretreatment is beneficial and if it can block the pancreatic DNA binding of the transcription factor nuclear factor-kappaB (NF-kappaB) and proinflammatory cytokine synthesis during cholecystokinin-octapeptide (CCK)-induced acute pancreatitis in rats. ⋯ Methylprednisolone pretreatment ameliorated many of the examined laboratory (the pancreatic weight/body weight [p.w./b.w.] ratio, the serum amylase activity, the plasma trypsinogen activation peptide concentration, the pancreatic levels of tumor necrosis factor-alpha and interleukin-6, the degree of lipid peroxidation, protein oxidation, nonprotein sulfhydryl group content and the pancreatic myeloperoxidase activity) and morphological parameters of the disease. Methylprednisolone pretreatment did not influence pancreatic NF-kappaB DNA binding, but decreased proinflammatory cytokine synthesis in this acute pancreatitis model. The findings suggest that the anti-inflammatory effect of large doses of methylprednisolone in secretagogue-induced pancreatitis occurs downstream of NF-kappaB DNA binding, and that increased pancreatic HSP72 synthesis may play a role in the protective effect of the drug.
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The Cl(-) channel blockers, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) or 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid (SITS) dose-dependently protected against oxygen-glucose deprivation in cultured rat cortical neurons. DIDS or SITS attenuated oxygen-glucose deprivation-induced increases in extracellular glutamate concentrations and intracellular Ca(2+). DIDS or SITS provided moderate protection against N-methyl-D-aspartate (NMDA) toxicity and decreased NMDA receptor-mediated increases in intracellular Ca(2+). ⋯ Neurotoxicity by exogenous glutamate was not prevented by SITS and was exacerbated by DIDS. Reductions in oxygen-glucose deprivation-induced increases in intracellular Ca(2+) levels underlie neuroprotection by DIDS and SITS. This was a reflection of lower extracellular [glutamate], direct inhibition of Ca(2+) influx through postsynaptic NMDA receptors, and possibly through other protective properties associated with DIDS and SITS.