The Effects Of Rho Kinase Inhibitor On The Expression Of NF-κB, FKN In Rats With Focal Cerebral Ischemia Reperfusion Injury

Background and ObjectiveCerebrovascular disease is a common disease which seriously damage human health and the ischemical accounts for more than half of the total cerebrovascular disease. With the medical level improving, thrombolytic therapy is more widely applied to clinic. Once thrombolysised, the ischemical brain tissue is restored blood flow and the dying brain cells are rescued,meanwhile it also brings a series of injuries which is the called ischemia reperfusion injury (I/R). According to recent studies, there are many factors involved in the ischemia and reperfusion injury which mainly including the following factors:excited amino acids toxicity, calcium overload, oxygen free radical damage, apoptosis and inflammatory reaction. Among them inflammatory reaction plays an important role and being the research focus worldwide all the time.Nuclear transcription factor-κ B is a nucleoprotein factor with the function of multi-directional regulation. It mainly exists in neurons, glial cells and cerebral vascular endothelial cells of the central nervous system, and it also participates in regulation of a variety of gene expression which playing an important role in the process of inflammatory reaction and immune response. Activated NF-κ B can increase the expression of adhesion molecule, inflammation factors and chemotactic factors promoting white blood cells easier to aggregate, adhere and invade in the ischemic area which aggravating the ischemic reperfusion injury.FKN(Fractalkine) which also named CX3CL1is the only member of chemotactic family. FKN which always expressed in the surface of activated vascular endothelial is no only a chemotactic factors, but also has adhesion function participating in transport, adhere of the white cell, speeding up the exudation of inflammatory factors, promoting the occurrence of inflammation cascade.Rho kinase is an important downstream substrate of the small G-protein Rho, which involved in the adhesion, migration of cells and also involved smooth muscle contraction or cytoskeletal protein reconstruction. As a Rho kinase inhibitor, Fasudil was initially used to relieve cerebral vasospasm of subarachnoid hemorrhage. Its cerebral protective effect maybe interrelate with inhibiting the activity of Rho kinase, which increasing the expression of eNOS in the ischemia brain, relaxing vascular, restraining the exudation of white blood cells, reducing inflammation.This study is to observes the effect of fasudil on the rat’s neurological function changes after reperfusion injury and the expression of NF-κ Bp65mRNA, FKNmRNA in ischemia brain by RT-PCR on the cerebral ischemia and reperfusion model which Explores the possible mechanisms of neuroprotection after cerebral ischemia and reperfusion by fasudil providing a scientific basis for clinical.Materials and methods90healthy SD male rats,with weight300to330g were randomly divided into three groups: Sham operation group, model group and fasudil treated group, each group has thirty rats; each group was further divided into three subgroups:6hours,12hours and24hours, each time point has ten rats. Zea-Longa’s suture method was used for middle cerebral artery ischemia-reperfusion injury model. The treatment group received an injection of Fasudil (15mg/kg) before preoperative1h. The other two groups were delivered equivalent normal saline (NS,1ml/Kg) by the same way. The neurological behavioral scores of rats were evaluated after each reperfusion time. when reached the corresponding time points the rats were sacrificed for NF-κ Bp65mRNA and FKNmRNA were examination by RT-PCR.Results1Neurological score:The sham group rats failed to show any neurologic deficits; The model group neurological defect were more serious than the other two groups and the defects were improved obviously by Fadsudil,there was a significant difference (p<0.05).2Expression of NF-κ Bp65mRNA in ischemia side Cerebral tissue:The sham group has a few expression in the three time points, and there were no obvious difference; meanwhile its expression is obviously in Model group of the three time points, with24h the highest; in Fasudil group of all the three time points its expression were significantly decreased, compared model group and there is a statistically significant difference (p<0.05).3Expression of FKNmRNA in ischemia side cerebral tissue:The sham group has a few expression in three time points, and there were no obvious difference; meanwhile its expression were obviously in Model group in three time points, with24h the highest; in Fasudil group its expression were decreased greatly in three time points compared with Model group and there was a statistically significant difference (p<0.05).Conclusions1The expression of NF-κ Bp65mRNA and FKNmRNA was significantly increased after cerebral ischemia reperfusion injury which may involved of the damage of reperfusion and inflammation response after.2The Rho kinase inhibitor fasudil could improve the cerebral ischemia neurological disorders and improve the prognosis.3Fasudil can reduce the damage of brain tissue after ischemia reperfusion properly through reducing the inflammation response and inhibiting the expression of NF-κ Bp65mRNA and FKNmRNA.