Effects Of Fasudil On The Behavior Of Of L-DOPA-induced Dyskinesia In A Rat Model Of Parkinson's Disease And The Possible Mechanisms

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Effect of fasudil on behaviour of L-DOPA-induced dyskinesia in a rat model of Parkinson's diseaseObjective:To establish the rat model of Parkinson's disease(PD)and levodopa-induced dyskinesia(LID)and observe the effect of Rho kinase inhibitor fasudil on the behavior of LID rats.Methods: A rat model of unilateral lesion of Parkinson's disease(PD)was established by stereotaxical injection of 6-hydroxy dopamine(6-OHDA)into the right forebrain bundle in SD rats.The successful rat model was screened by apomorphine induction.The PD rats were randomly divided into PD group,LID group,LID+fasudil low dose(5mg/kg)group and LID+fasudil high dose group(10mg/kg)group.Sham operated group as control was aslo set.The PD model rats were intraperitoneally injected with L-DOPA compound(25mg/kg L-DOPA,benserazide hydrochloride 6.25mg/kg)twice daily continued for 21 days to induce dyskinesias.Behavioral tests of abnormal involuntary movement(AIM)were recorded on day 7,14,19 and 21.The open field test was also conducted to test the locomotor activity of Parkinson's disease.Results: The present study found that Pulsatile treatment with levodopa induced AIM in PD rats,including orofacial?contralateral limb?axial intortion of trunk which were similar to LID in PD patients.Besides,with the prolonging of levodopa use time,AIM score was growing and the degree of dyskinesia became increasingly serious.Rho kinase inhibitor fasudil(high and low dose group)treatment can significantly reduce the abnormal involuntary movement of limbs,orofacial involuntary movement and axial abnormal involuntary movement,which were three subtypes of AIM score,as well as total AIM score.What's more,the therapeutic effect was dose dependent.At the same time,the results of open field test(Total distance,Crossing numbers,Rearing numbers,)also suggested that it could improve the motor symptoms of PD rats.Conclusion: In conclusion,fasudil,as a Rho kinase inhibitor,dose dependently ameliorated behavior of L-DOPA-induced dyskinesia in PD rats,without disturbing the efficacy of L-DOPA and can even improve motor symptoms of PD rats.Part ? Effect of fasudil on Rho kinase in L-DOPA-induced dyskinesia in a rat model of Parkinson's diseaseObjective: To evaluate the effect of Rho kinase inhibitor fasudil on the Rho kinase activity and expression of Rho kinase in substantia nigra and striatum of rats.Methods: A rat model of unilateral lesion of Parkinson's disease(PD)was established by injection of 6-OHDA into the right forebrain bundle in SD rats.The PD model rats were sequentially received intraperitoneal injection of L-DOPA therapy and Rho kinase inhibitor fasudil and then observe effect of fasudil treatment on behavior changes in this rat model of levodopa induced dyskinesia.All the rats were sacrificed and decapitated.After extraction of substantia nigra and striatum tissue of rats,formaldehyde solution fixation,paraffin embedding and some other steps,ELISA and immunohistochemistry methods were used to detect Rho kinase activity and expression of Rho kinase.Results: In this part of study,compared with PD rats,we observed increased expression of Rho kinase and upregulation of Rho kinase activity level in LID rats.Rho kinase activity analysis revealed that nigrostriatal Rho kinase activity dramatically increased in LID rats compared to PD rats.Compared with L-DOPA rats,the level of Rho kinase activity was increased in rats with L-DOPA+Fasudil.Results of immunohistochemistry could also show this similar trend.Conclusion: Intraperitoneal injection of fasudil can reduce Rho kinase activity and downregulate expression of Rho kinase in levodopa induced dyskinesia in Parkinson disease rats.Part ? Effects of Fasudil on L-DOPA-induced dyskinesia in a rat model of Parkinson's diseaseand the Possible MechanismsObjective:To establish the rat model of Parkinson's disease(PD)and levodopa-induced yskinesia(LID)and observe the effect of Rho kinase inhibitor fasudil on the behavior of LID rats and explore its underlying mechanisms.Methods: A rat model of unilateral lesion of Parkinson's disease(PD)was established by stereotaxical injection of 6-hydroxy dopamine(6-OHDA)into the right forebrain bundle in SD rats.The successful rat model was screened by apomorphine induction.Validated 6-OHDA-lesioned rats of LID group were administrated twice-daily with L-dopa plus benserazide for 3 weeks to induce a rat model of dyskinesia.Moreover,other 6-OHDA-lesioned rats were treated with fasudil(5mg/kg/day,10mg/kg/day,intraperitoneally,respectively)combination with L-dopa treatment.After the last administration,the rats were decapitated and substantia nigra and striatum of rats were extracted.ELISA and immunohistochemistry were used to detect the expression of microglial activation and proinflammatory cytokines(IL-1?,TNF-?,i NOS)and oxidative stress(MDA,SOD)in substantia nigra and striatum.Results: Rho kinase inhibitor fasudil significantly reduced AIMs scores in a dose-dependent manner without compromising the anti-PD effect of levodopa.Simultaneously,dyskinetic animals displayed significantly higher levels of Rho kinase,pro-inflammatory factors(IL-1?,TNF-?,i NOS)and a marked increase in microglial response which was visualized by IBA-1 immunoreactivity in the lateral striatum and the substantia nigra.Interestingly,treatment with fasudil in combination with L-dopa inhibits the microglial response accompanied by the suppression of inflammatory responses associated with ROCK inhibition.It also significantly reduced AIMs scores in a dose-dependent manner without compromising the anti-PD effect of levodopa.In addition,on the level of molecular biology we also observed that it can reduce oxidative stress by decreasing MDA content and increasing SOD activity.Conclusion: All the present findings indicate that inhibition of neuroinflammation and amelioration of oxidative stress may be responsible for the potential anti-dyskinetic effects,suggesting the rho kinase as a new target for LID treatment in PD patients.