| Recent years,people found the purine signaling molecules and their receptors play an important role in neural development and its physiological functions.They are mediated by the interaction between neurons and glia,participating in the regulation of neurogenesis,neuronal migration,axon growth and physiological process.Morever,purine signaling molecules and glia activation is of great improtance in a variety of neuropathy,such as stroke,traumatic brain injury,Alzheimer's disease,multiple sclerosis,and amyotrophic lateral sclerosis,epilepsy,nerve pain.Minocycline,one kind of seeond generation of tetracycline derivative,is easier to get through the blood brain barrier to the central nervous system than the other tetracycline drugs.Having this advantage,minocycline has been approved to be benefical for a variety of neurologic disease models.But in the study of experimental ischemia experiment study,the effect of minocycline is different.Our research aims to observe the effect of minocycline on microglia activation and P2X7 receptor expression after cerebral ischemia.1 The effect of minocycline on neurons damage after cerebral ischemia in ratsObjective:To study the effect of minocycline on neurons damage after cerebral ischemia in rats.Methods:Cerebral ischemia was induced by middle cerebral artery occlusion(MCAO)in rats.Using immunohistochemistry,the effect of minocycline on NeuN expression in rat brain was observed.Results:NeuN positive neurons were widely distributed in the rat cortex and striatum,and the number of NeuN positive neurons had no difference.But compared with MCAO group,the amount of NeuN expression was significantly lower(P<0.05)in minocycline 22.5mg/kg,45mg/kg group.At the same time,the morphology of NeuN was distinct.In the sham group,the nuclei were round or ovoid.In the MCAO group,NeuN was in spindle distribution,combing with the DAPII nuclear staining results,suggesting that the nuclei were shrink.Treated with minocycline 22.5mg/kg,45mg/kg,the NeuN was distributed in more small fusiform or triangle.Conclusion:The above results suggested that minocycline could aggravate neuron damage after cerebral ischemia.2 The effect of minocycline on nNOS after cerebral ischemia in ratsObjective:To study the effect of minocycline on nNOS after cerebral ischemia in rats.Methods:Using Western Blot method,we observed the effect of minocycline on nNOS expression after cerebral ischemia in rats.Results:The expression of nNOS was significantly decreased after MCAO injury(P<0.05).And minocycline 45mg/kg could upregulate the content of nNOS compared with the injury of MCAO group(P<0.05).Conclusion:The results indicated that minocycline can increase nNOS expression after cerebral ischemia.3 The effect of minocycline on microglia activation after cerebral ischemia in ratsObjective:To study the effect of minocycline on microglia activation after cerebral ischemia in rats.Methods:With immunohistochemistry method and microglia specific markers Ibal,the effect of minoeycline on microglia activation after cerebral ischemia in rats was studyed.Results:The number of Ibal positive microglia of each group was of no significant difference.However,MCAO injury upregulated the expression of Ibal on microglia in the cortex and striatum(P<0.05,compared with the sham),and minocycline did not interfere the upregulation.In addition,the morphology of microglia had certain differences after cerebral ischemia.The processes of microglia distributed radially in the sham group.After MCAO injury,the processes length was longer,the number was increased,and cell volume was larger.And the microglia had the similar cell morphology in minocycline group.Conclusion:The results indicated that minocycline could not inhibit microglia activation after cerebral ischemia in rats.4 The effect of minocycline on the release of IL-1? and TNF-? after cerebral ischemia in ratsObjective:To study the effect of minocycline on the release of IL-1? and TNF-? after cerebral ischemia in rats.Methods:The influence of minocycline on the release of IL-1? and TNF-? in cerebral ischemia rats was detected by enzyme-linked immunosorbent assay.Results:The IL-1? and TNF-? concentrations were similar in MCAO injury group and the sham group;compared with MCAO injury group,the IL-1? and TNF-? concentrations were increased by 45%and 40%with 22.5mg/kg minocycline,and the distinction was significant(P<0.05).Conclusion:After cerebral ischemia,IL-1? and TNF-? hadn't been released into the intercellular space in rats,but the minocycline could improve the release of them.5 The effect of minocycline on P2X7 receptor expression after cerebral ischemia in ratsObjective:To study he effect of minocycline on P2X7 receptor expression after cerebral ischemia in rats.Methods:With immunohistochemistry method,the effect of minocycline on P2X7 receptor expression after cerebral ischemia was observed.Results:P2X7 receptor was widely distributed in the cortex and striatum,and expressed in neurons and microglia.In the two regions,the number of P2X7 receptor positive cells had no difference between the groups.But in the striatum,22.5mg/kg,45mg/kg minocycline decresed the number of P2X7 receptor positive cells by 54.93%and 54.93%respectively(P>0.05,compared with the MCAO group).In addition,the P2X7/NeuN and P2X7/Ibal immunohistochemical results show that in the rat cortex and striatum,the number of P2X7/NeuN and P2X7/Ibal double labed cells had no significant difference(P>0.05).However in the striatum region,compared with the MCAO group,minocycline 22.5mg/kg,45mg/kg group reduced the amount of P2X7/NeuN double positive cells by 50.93%and 28.90%.Conclusion:Results showed that,after cerebral ischemia P2X7 receptors were not activated,and minocycline had a tendency to inhibit P2X7 receptors expression in neurons in striatum.Above all,minocycline had no obvious effect on P2X7 receptor expression and microglia activation,but it can increase neuronal damage after cerebral ischemia,the damage may be related to the promotion of nNOS expression,and release of IL-1? and TNF-?. |
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