吡贝地尔对帕金森病模型大鼠脑多巴胺D2受体的影响

目的研究常用抗帕金森药多巴胺受体激动剂吡贝地尔对脑多巴胺D2受体的影响。方法立体定位右侧纹状体注射6-羟多巴胺制备偏侧帕金森病大鼠模型,模型成功后予吡贝地尔灌胃治疗30mg/(kg·d)]5周。分4组(正常组、术后4周帕金森病模型大鼠组、术后9周帕金森病模型大鼠经吡贝地尔治疗组、术后9周帕金森病模型大鼠未治疗组)行125I-依匹必利(125I-epidepride)大鼠脑多巴胺D2受体放射自显影。图像分析得到纹状体与小脑的平均光密度值,计算并比较各组左、右两侧脑多巴胺D2受体的特异性放射性摄取比值(纹状体/小脑-1)的变化。结果正常大鼠脑多巴胺D2受体对依匹必利的特异性放射性摄取比值左、右两侧差异无统计学意义;成为帕金森病模型后,右侧(损毁侧)比值较正常稍升高,但差异无统计学意义;未治疗组帕金森病模型大鼠双侧比值较刚成模型时均明显降低,右侧(损毁侧)比值仍较左侧高;经吡贝地尔治疗后,双侧比值较未治疗组进一步降低,右侧(损毁侧)降低甚,比值较左侧低。结论长期吡贝地尔治疗可能会使帕金森病模型大鼠双侧脑多巴胺D2受体的数量减少,损毁侧减少为甚。

The effect of Piribedil on dopamine D2 receptor in Parkinsonian rat models

Objective To investigate the effect of Piribedil on dopamine D2 receptor in hemiparkinsonian rat models.Methods Hemiparkinsonian rat models were induced by injection of 6-OHDA into right striatum.Four weeks after the procedure,they were fed with Piribedil for 5 weeks.There were four groups in this study,including normal group,Parkinsonian rat model group,Parkinsonian rat model group taking Piribedil(Piribedil group)and Parkinsonian rat model group without Piribedil(non-Piribedil group),five rats in each group.The dopamine D2 receptors of rats in each group were performed imaging by radioautography with 125I-epidepride.Optical density of striatum and cerebellum was measured through image analysis.At last the average ratios of specific radioactivity uptake of bilateral dopamine D2 receptors(Striatum/Cerebellum-1)were evaluated and compared.Results The specific radioactivity uptake ratios of dopamine D2 receptor had no difference between bilateral striatum in normal rats.4 weeks after operation(Parkinsonian rat model group),the ratio of dopamine D2 receptor increased slightly in right striatum(lesioned side),but there was no significant difference between bilateral striatum.9 weeks after operation(non-Piribedil group and Piribedil group),ratios were significantly decreased in bilateral striatum.Ratio was higher in right(lesioned)striatum than it was in left side in non-Piribedil group,but it was opposite lower in right(lesioned)side in Piribedil group.Conclusions Long-term administration of Piribedil maybe interfere with the number of dopamine D2 receptors in bilateral striatum of hemiparkinsonian rat models,more in lesioned side.