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Journal of The Korean Society of Emergency Medicine 2002;13(3): 329-340. |
Effect of Melatonin on Expression of c-Jun Proteins and BDNF mRNA in Transient Global Ischemia-Reperfusion Injury of Rat Brain |
Yong Hwan No, Dai Han Wi, Jae Hwang Park |
Department of Emergency Medicine, Wonkwang University, School of Medicine, Iksan, Korea. great@wonkwang.ac.kr |
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ABSTRACT |
PURPOSE: The purpose of this study was to investigate the effect of systemic treatment of melatonin known as a potent free radical scavenger on expression of c-Jun proteins and brain-derived neurotrophic factor (BDNF) mRNA in transient global ischemia-reperfusion injury of rat brain.
METHODS: Spargue-Dalwey rats were used and divided into three groups: ischemia group, ischemia group pretreated with melatonin, ischemia group posttreated with melatonin. Brain ischemia-reperfusion injury induced by occlusion of bilateral carotid and vertebral arteries (4-vessel occlusion) for 15 min followed by recirculation of cerebral blood flow. Animals were received intraperitoneal injection of melatonin (10 mg/kg) either 30 min before ischemia (pretreatment) or 0 min after reperfusion (posttreatment).
Four vessel occlusion-reperfusion produced ischemic injury in major forebrain structures such as striatum, cortex, hippocampus in the finding of triphenyltetrazolium chloride (TTC) staining. Spectrophotometric assay for formazan, an end-product of TTC showed increased value of formazan formation in ischemic area of the brain posttreated with melatonin 24 hours after the ischemia-reperfusion injury.
RESULTS: Posttreatment with melatonin caused a significant decreased in number of c-Jun immunoreactive neurons in CA1 region of the hippocampus after ischemia-reperfusion insult.
Furthermore, autoradiographic density for BDNF mRNA in the hippocampus and cortex was increased by systemic treatment with melatonin especially in posttreatment group.
CONCLUSION: These results suggest that melatonin treatment results in an attenuation of ischemic damage caused by ischemia-reperfusion in nueronal cells of the sensitive areas of rat brain. |
Key words:
Ischemia-reperfusion injury, Melatonin |
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