偏侧帕金森病大鼠基底神经节亚区氨基酸递质及GABAA受体亚单位mRNA的表达

Contents of amino acid neurotransmitters and expression of GABAA receptor subunits＇ mRNA in subareas of basal ganglia in unilateral rat model of Parkinson＇ s disease

目的研究偏侧帕金森病（PD）大鼠基底神经节亚区新纹状体、内侧苍白球、外侧苍白球和丘脑底核氨基酸递质含量以及GABAA型受体（GABA。）mRNA表达变化。方法6一羟基多巴胺（6-OHDA）脑内立体定位注射制成偏侧PD大鼠模型，采用高效液相色谱分析仪（HPLC）测定新纹状体、内侧苍白球、外侧苍白球和丘脑底核内氨基酸递质的含量；NorthemELISA法测定GABA。受体α1、α2、β2/3、γ2亚单位mRNA表达。结果偏侧PD大鼠损毁侧新纹状体、内侧苍白球、外侧苍白球和丘脑底核内的GABA，新纹状体、外侧苍白球和丘脑底核内的谷氨酸，以及丘脑底核内的天冬氨酸、甘氨酸与未损毁侧相同解剖部位相比含量明显增加，差异均有统计学意义。偏侧PD大鼠新纹状体：损毁侧GABAA受体α（105．3±24．5）、B2／]（113．7±15．3）亚单位与未损毁侧（186．7±37．2、157．4±32．4）比较，其mRNA表达水平显著下降（t=5．16、3．45，P〈0．01）；偏侧PD大鼠内侧苍白球：损毁侧GABA。受体α1、α2、β2/3亚单位与未损毁侧比较其mRNA表达水平显著升高（其中α1P〈0．05，α2、β2/3 P〈0．01）；偏侧PD大鼠外侧苍白球：损毁侧GABA。受体α2（179．1±26．8）、β2／3（154．7±37．8）亚单位与未损毁侧（219．3±19．7、231．1±55．8）比较，其mRNA表达水平显著下降（t=3．42、3．21，P〈0．01）；偏侧PD大鼠丘脑底核：损毁侧GABAA受体α1、α2、β2/3、γ2亚单位与未损毁侧比较其mRNA表达水平均显著下降（其中α1、α2、β2/3、P〈0．01，γ2 P〈0．05）。结论偏侧PD大鼠基底神经节亚区氨基酸递质含量以及GABA。受体亚单位mRNA表达水平的改变可能参与了PD的发病。

Objective To explore contents of amino acid neurotransmitters and expression of GABAA receptor subunits＇ mRNA in subareas of basal ganglia in unilateral rat model of Parkinson＇ s disease （PD）. Methods The rat model of PD was established through right unilateral intranigral microinjection of 6-hydroxydopamine （6-OHDA） in this study. Thawed samples were taken form neostriatum （Str）, globus pallidus internus （GPi） , globus pallidus externum （GPe） and subthalamic nucleus （STN） , then contents of amino acid neurotransmitters were analyzed by established high performance liquid chromatography （HPLC） -electrochemical detection methods. The subunits α1, α2, β2/3 and γ2 of GABAA receptor in Str, GPi, GPe and STN wre examined with Northern Enzyme linked immunosorbent assay （ELISA）. Results The content of GABA in Str, GPi, GPe and STN of diseased side were significantly increased as compared with undiseasedside. The level of glutamic acid （Glu） in Str, GPe and STN and contents of aspartic acid （Asp） and glycine （Gly）in STN of the diseased side were significantly increased. In Str, there was a significant decrease of mRNA expression either in the subunit α1 （ 105.3 ± 24.5 ） or in the subunit [β2/3 （ 113.7 ± 15.3） of GABAA receptor in the diseased side as compared with the undiseased side （ 186. 7 ± 37.2,157.4 ±32.4,t =5.16,3.45;P 〈0.01）. In GPi, there was a significant increase of mRNA expression in the subunit α1 （ P 〈 0.05 ） and α2, β2/3 （ P 〈 0. 01 ） of GABAA receptor in lesion side. In GPe, there was a significant decrease of mRNA expression in the subunit α2 （ 179.1 ± 26. 8 ） and [β2/3 （ 154.7 ±37. 8） of GABAA receptor in the diseased side（219. 3 ±19. 7, 231.1 ±55.8 ,t =3.42,3.21 ;P 〈0. 01 ）. In STN of right unilateral 6-OHDA lesion rat, there was a significant decrease of mRNA expression both in the subunit α1, α2 and β2/3 （ P 〈 0. 01 ） of GABAA receptor and in the subunit γ2 （ P 〈 0. 05 ） of GABAA receptor in the diseased side. Conclusions Changes of amino acid neurotransmitter contents and GABAA receptor subunits＇ mRNA expressional level in subareas of basal ganglia may be involved in PD.