| Objective: To establish a model of focal cerebral ischemia-reperfusion in rats with hyperlipidemia,and to intervene with different doses of monosialotetrahexosylganglioside(GM1)to detect GM1 after cerebral ischemia-reperfusion injury.Neurological function score,cerebral infarction area,pathological changes,brain water content,number of apoptotic cells,and dynamic expression of TNF-? and cytokine signal transduction inhibitor-3(SOCS-3),and GM1 on high fat Protective effects and possible mechanisms of cerebral ischemia-reperfusion injury in rats with hypoxemia.Methods: 1.Preparation of hyperlipidemia rat model;2.Successfully prepared hyperlipidemia rats were randomly divided into four groups,sham operation group(sham group)30,cerebral ischemia reperfusion group(CIRI group)30,30 small dose GM1 group,30 high dose GM1 group.5 observation time points per component were 6h,12 h,24h,48 h and 72 hours after reperfusion,except for 10 rats at 24h(5 of which were used for TTC staining to calculate the volume of cerebral infarction),each time Point 5 SD rats.3.Follow the modified suture method,establish a model of cerebral ischemia-reperfusion embolization under the microscope,5 minutes and 60 minutes after cerebral ischemia,intraperitoneal injection of GM1 twice,high dose(60 mg / Kg),low dose(15 mg / Kg)intraperitoneal injection of GM1,reperfusion for 90 min after ischemia,the plug was removed,blood supply was restored,and the model was evaluated for success by scoring the neurological deficit.The water content of brain tissue was determined by dry-wet weight method.HE staining method was used to understand the pathological condition of cerebral infarction in rats at various time points.The immunohistochemical method was used to determine the TNF-? and SOCS-3 immunoreactive cells in rat brain tissue at different time points.The expression of the cells was detected by TUNEL method at different time points after operation.Results: 1.Changes in neurological function scores: Compared with the sham operation group,the scores of the cerebral I/R group and the high-low dose group were significantly decreased(P<0.05).Compared with the cerebral I/R group,the high-low dose group was The neurological deficit scores increased at 12 h to 72 h(P<0.05),and increased significantly in the high-dose group(P<0.05).In the group,the cerebral ischemia-reperfusion group and the high-low dose group were 6 h after surgery.There were significant differences between the 12 h,48 h,72 h and 24 h time points(P<0.05).2.Pathological changes of ischemic brain tissue in rats: After HE staining in the sham-operated group,the cell membrane was intact under the light microscope,the cytoplasm was abundant,the neurons were arranged neatly,the nucleus was round or elliptical,and there was no interstitial edema.And inflammatory cell infiltration;cerebral I/R group showed typical ischemic changes,cell gap increased,the number of neurons decreased significantly,the nucleus condensed and deep-stained,the nucleolus disappeared,vacuolar-like changes,interstitial edema Inflammatory cell infiltration;compared with the cerebral I/R group,the number of inflammatory cell infiltration and cell necrosis in the ischemic area at the same time point in the high-and low-dose groups was relatively reduced,and cell edema and vacuolar degeneration were alleviated.3.Determination of water content in brain tissue: Compared with sham operation group,ischemia-reperfusion group,high-low dose group were significantly higher than sham operation group,the difference was statistically significant(P<0.05);and I/R group Compared with the I/R group which using GM1 intervention,the water content of brain tissue in the high-dose group was lower than that in the I/R group(P<0.05).The water content in the low-dose group was higher than that in the cerebral I/R group at 12 h,24h,48 h and 72 h.The time point was low(P<0.05),but there was no significant difference between the 6h and cerebral I/R group(P>0.05).The high-dose group had lower brain water content in the lower dose group(P< 0.05).4.Determination of cerebral infarction volume in rats: The body volume of cerebral infarction was measured in 24 hours after operation in four groups of rats.No cerebral infarction(0.00±0.00 mm3)was found in the sham operation group.Compared with the sham operation group,cerebral ischemia.The cerebral infarction lesions(168.34±3.15 mm3)appeared in the perfusion group 24 hours after operation(P<0.05).Compared with the cerebral I/R group,the cerebral infarction volume in the high and low dose groups was significantly decreased(P<0.05).The decrease was more pronounced in the high dose group(P<0.05).5.Apoptotic cells in ischemic brain tissue: only a small number of apoptotic cells were observed in the sham operation group.Apoptotic cells were observed in the I/R group and the high-low dose group,starting from 6h and peaking at 48 h.Then decreased,and further decreased at 72 h,but still expressed,compared with the sham operation group,both were statistically significant(P<0.05);compared with the I/R group,the high-dose group and the low-dose group corresponded At the time point,the expression of apoptotic cells was decreased,the difference was statistically significant(P<0.05),and the decrease was more significant in the high-dose group(P<0.05).6.Expression of TNF-? positive cells in rat brain tissue: TNF-? expression was observed in cerebral I/R group and high-low dose group,and it was expressed at 6h,increased at 12 h,peaked at 24 h,48h The decrease was still small,and there was still a small amount of expression in 72 hours.The trend of the three groups was basically the same,which was higher than that of the sham operation group(P<0.05).Compared with the cerebral I/R group,the expression of TNF-? was decreased in the high and low dose groups.The decrease in the high-dose group was more significant,and the difference was statistically significant(P<0.05).7.Expression of SOCS-3 positive cells in rat brain tissue: Compared with sham operation group,SOCS-3 expression was observed in cerebral I/R group and high-low dose group,and the expression was higher than that in sham operation group at each time point.Within the group,SOCS-3 was expressed at 6h,continued to increase at 12 h,peaked at 24 h,decreased at 48 h,and still showed a small amount at 72 h.The trend of the three groups was basically the same;compared with the cerebral I/R group,both of high and low dose groups was significantly increased(P<0.05),and the high dose group was more obvious,the difference was statistically significant(P<0.05).Conclusion: 1.On the basis of free-feeding + modified hyperlipidemia rats fed with high-fat diet,the model of CIRI was established by modified suture method,which can fully simulate the pathophysiological evolution process after cerebral infarction in humans.It is an ideal animal model for studying CIRI with good reproducibility and operability.2.The expression of TNF-? and SOCS-3 increased in a certain period of time after cerebral ischemia,suggesting that SOCS-3 may play a role in inhibiting TNF-? and/or reducing apoptosis.3.GM1 may up-regulate the expression of SOCS-3,inhibit the expression of pro-inflammatory cytokine TNF-?,inhibit cell apoptosis,thereby reducing brain edema,reducing cerebral infarction area,promoting neurological recovery and exerting brain protection. |
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