The Effect Of Melatonin On Autophagy Induced By Cerebral Ischemia Reperfusion Of SD Rat

Objective: Research on the autophagic activity changes of SD rat with cerebralischemia reperfusion within a week, and the effect of melatonin on autophagy inducedby cerebral ischemia reperfusion.Methods:(1）Experimental groups: sham-operated group: Analog-only surgery,without blocking the artery, were killed after a day, as a control group; MCAO group:Implement the left artery ischemia90min, followed by reperfusion1,3,5,7days.Melatonin treated group: Treat with melatonin at the time of reperfusion, then every24h administered once.(2) Sample collection: TTC staining to determine the ischemicarea, take the corresponding ischemia cortex, hippocampus, and corresponding part ofthe right side cortex and hippocampus.(3)The expression of autophagy-relatedprotein LC3, Beclin1,p70s6k,p-p70s6k were detected by Western blot.Result:1）MCAO group: with reperfusion time prolonged, western blot of corticaltissue showed that the level of LC3-Ⅱsignificantly increased in the first day ofreperfusion, and to be the highest(p<0.05),the third,fifth day showed a slight decrease,but compared with the sham group, there is still a significant increase (p<0.05).theseventh day have a little rebound. The expression of beclin1in the cortex showed afirst increase then decrease with time trend. The first, third, fifth day showed a growthtrend, and the third day have a significant increase(p<0.05). The seventh day showeda decrease, and nearly the same level with sham group. The level of LC3-Ⅱinhippocampus consistent with the time trend of cortex. However, compared with thesham group, no significant difference (p>0.05), Beclin1in hippocampus share thesame trend with cortex. Both cortex and hippocampus in p70s6k expression showingan upward trend after the decline, Significant difference (P <0.05) compared with thesham group. p-p70s6k/p70s6k ratio both showed an upward trend in the wholeprocess, and the hippocampus p-p70s6k/p70s6k significantly increased compared with the sham group (P <0.05).2) melatonin treated group: The level of LC3-Ⅱ bothin cortex and hippocampus have no difference with the sham group in the first day.The following day seems to increase slowly, but no significant difference with thesham group (p>0.05).Beclin1levels no obvious ups and downs of the entire process,and there is no significant difference with the sham group (p>0.05).Conclusion: Ischemia-reperfusion induced LC3-II, Beclin-1upregulation in SD ratcortex and hippocampus and promote autophagy, Meanwhile the ratio ofp-p70s6k/p70s6k With reperfusion time prolonged showed an increasing trend.Aftertreatment with melatonin, the expression of LC3-II, Beclin-1in the first day did notshow increased.In the following days,they showed a slowly increasing.Contrary toischemia-reperfusion group trends.That melatonin may regulate autophagy tomaintain a certain level,So as to reduce the damage caused by ischemia andreperfusion.