The Protective Effect On Cerebral Ischemia Reperfusion Injury During Carotid Endarterectomy Perioperative Period

Objective:Explore the protective function of melatonin(MT)in human cerebral ischemia reperfusion injury during perioperative period of carotid artery stenosis,and attempt to illustrate the mechanism for further research.Methods:60 participants under carotid endarterectomy(CEA)were divided into 3 groups randomly:melatonin group,placebo group and blank control group.Besides routine clinical treatment,6mg qd oral melatonin,isodose placebo and no other treatment were offered to the groups separately.Peripheral venous serum were collected at the time point of pre-anesthesia,reconstruction of carotid artery,6 hour after operation and 24 hour after operation,to analyze the degree of cerebral ischemia reperfusion,oxidation and inflammation.Results:The average S100B concentration of melatonin group at 6 hours after operation is 136.05±45.65pg/ml,while 221.35±44.57pg/ml in placebo group and 214.36±39.51pg/ml in blank control group,with a reduction of 38.5%and 36.5%(p<0.05)separately.The average S100B concentration of melatonin group at 24 hours after operation is 109.52±41.34pg/ml,while 220.25±34.64pg/ml in placebo group and 212.50±31.67pg/ml in blank control group,with a reduction of 50.2%and 48.4%(p<0.05)separately.The average Nrf-2 concentration of melatonin group at 6 hours after operation is 1339.70±202.73pg/ml,while 994.45±203.89pg/ml in placebo group and 1018.69±196.86pg/ml in blank control group,with an increment of 1.35 times and 1.32 times(p<0.05)separately.The average SOD concentration of melatonin group at 6 hours after operation is 1847.42±198.63pg/ml,while 1496.49±150.09pg/ml in placebo group and 1534.43±100.15pg/ml in blank control group,with a increment of 1.23 times and 1.20 times(p<0.05)separately.The average IL-6 concentration of melatonin group at 6 hours after operation is 16.800±3.916pg/ml,while 28.207±3.563pg/ml in placebo group and 29.255±6.555pg/ml in blank control group,with a reduction of 40.4%and 42.6%(p<0.05)separately.The average IL-6 concentration of melatonin group at 24 hours after operation is 20.862±3.400pg/ml,while 27.403±3.487pg/ml in placebo group and 28.170±3.776pg/ml in blank control group,with a reduction of 23.9%and 25.9%(p<0.05)separately.The average TNF-a concentration of melatonin group at 24 hours after operation is 24.408±6.494pg/ml,while 35.058±5.213pg/ml in placebo group and 34.398±5.815pg/ml in blank control group,with a reduction of 30.3%and 29.0%(p<0.05)separately.The average NF-?B p65 concentration of melatonin group at 6 hours after operation is 869.78±138.22pg/ml,while 1077.70±207.75pg/ml in placebo group and 1168.58±148.21pg/ml in blank control group,with a reduction of 19.3%and 25.6%(p<0.05)separately.The average eNOS concentration of melatonin group at 6 hours after operation is 306.06±64.43pg/ml,while 207.98±59.64pg/ml in placebo group and 170.63±64.77pg/ml in blank control group,with a increment of 1.47 times and 1.79 times(p<0.05)separately.The average eNOS concentration of melatonin group at 24 hours after operation is 352.78±67.76pg/ml,while 208.88±48.69pg/ml in placebo group and 188.49±67.39pg/ml in blank control group,with a increment of 1.69 times and 1.90 times(p<0.05)separately.Conclusion:Melatonin may have the protective function for cerebral ischemia reperfusion during perioperative period of carotid artery stenosis.Suppression of the oxidation and inflammation induced by ischemia reperfusion reduce the cerebral exposure to enormous free radical and inflammatory factors.The upregulation of Nrf-2 pathway and downregulation of NF-?B pathway may contribute to the protective effect.