去松果体与去势对帕金森病模型大鼠中脑多巴胺神经元的影响

Effect of pinealectomy and gonadectomy on dopaminergic neurons of mesencephalon in Parkinson＇ s disease model rats

目的探讨去松果体（pinealectomy，Px）与去势（gonadectomy、GDX）对帕金森病（par-kinson＇s disease，PD）模型大鼠中脑多巴胺（dopamine，DA）神经元的影响。方法80只雄性Wistar大鼠按照随机数字表法分为NS组、N＋6-羟基多巴胺（6-hydroxydopamine，6-OHDA）、PX＋6-OHDA、GDX＋6-OHDA、PX＋GDX＋6-OHDA5组，每组16只。术后60d，于大鼠中脑黑质致密部（substantia nigra pars compacta，SNc）、腹侧被盖区（ventral tegumental area，VTA）注入6-OHDA，14d后处死取材。HE染色观察胶质细胞增生情况，胶质纤维酸性蛋白（glial fibrillary acidic protein，GFAP）染色观察星形胶质细胞数量，Tunel染色观察细胞凋亡数量，免疫组化SP法检测酪氨酸羟化酶（tyrosine hydroxylase，TH）阳性细胞和纤维及凋亡相关蛋白Bax、Bcl2的变化。结果（1）SNc、VTA胶质细胞增生数按照组Ns、N＋6。OHDA、PX＋6．OHDA、GDX＋6．OHDA、PX＋GDX＋6-OHDA顺序依次增加（HE染色：Hc=280．178，P〈0．01；Hc=334．260，P〈0．01）（GFAP染色：Hc=367．081，P〈0．01；Hc=376．049，P〈0．01）；（2）SNc、VTA细胞凋亡数按照组NS、N＋6．OHDA、PX＋6-OHDA、GDX＋6-OHDA、PX＋GDX＋6-OHDA顺序依次增加（Hc=344．401，P〈0．01；Hc=326．198，P〈0．01）；（3）SNc、VTA TH（＋）阳性细胞数按照组NS、N＋6-OHDA、PX＋6-OHDA、GDX＋6-OHDA、PX＋GDX＋6-OHDA顺序依次显著减少（Hc=366．532，P〈0．01；Hc=372．565，P〈0．01）；（4）SNc、VTATH（＋）阳性细胞和纤维灰度值按照组NS、N＋6-OHDA、PX＋6-OHDA、GDX＋6-OHDA、PX＋GDX＋6-OHDA顺序依次增加（F=517．239，P〈0．01；F=526．758，P〈0．01）；（5）Bax表达：NS组弱阳性，N＋6-OHDA组阳性，余三组强阳性；Bcl2表达：各组均弱阳性。结论PX、GDX显著加重6-OHDA神经毒性，GDX作用大于PX，PX＋GDX作用最强。

Objective To investigate the effect of PX and GDX on dopaminergic neurons of mesencephalon in Parkinson＇ s disease model rats. Methods Eighty male Wistar rats were randomly divided into five groups： NS, N＋6-OHDA,PX＋6-OHDA,GDX＋6-OHDA and PX＋GDX＋6-OHDA group;16 rats in each group. 60 days after operation,6-OHDA was injected into SNc and VTA in the right side of the mesencephaion. After 14 days,the rats were sacrificed. HE staining was used to observe the proliferation of glial cells. The number of astrocytes was observed by GFAP staining. The number of apoptotic cells was observed by TUNEL staining. Immunohistochemical staining （S-P Method） was used to detect the changes of TH-positive cells and fiber, apoptosis-related proteins Bax and Bcl2. Results （ 1 ） The numbers of proliferated glial cells in SNc and VTA were significantly increased according to the following sequence： NS, N＋6-OHDA, PX ＋6-OHDA, GDX＋6-OHDA, and PX＋GDX＋6-OHDA （ HE staining ： Hc = 280.178, P〈0.01 ; Hc = 334.260, P〈 0.01 ） （ GFAP staining ： Hc = 367.081 ,P〈0.01 ;Hc= 376.049,P〈0.01 ）. （2） The numbers of apoptotic cells in SNc and VTA were significantly increased according to the following sequence： NS, N＋6-OHDA,PX＋6- OHDA,GDX＋6-OHDA,and PX＋GDX＋6-OHDA （He = 344.401,P〈0.01 ;He = 326.198,P〈0.01 ）. （3） The numbers of TH （＋） ceils in SNc and VTA were significantly decreased according to the following sequence ： NS,N＋6-OHDA, PX ＋ 6-OHDA, GDX ＋ 6-OHDA, and PX＋GDX＋ 6-OHDA （ He = 366.532, P〈0.01 ; Hc = 372.565 ,P〈0.01 ）. （4） The gray values of TH（＋） positive cells and fiber in SNc and VTA were significantly increased according to the following sequence： NS,N＋6-OHDA, PX＋6-OHDA, GDX＋6-OHDA and PX＋ GDX＋6-OHDA （F=517.239,P〈0.01;F=526.758,P〈0.01）. （5） Bax expression： weakly positive in NS group, positive in N＋6-OHDA group, and strongly positive in remaining three groups; Bel2 expression： weakly positive in eaeh group. Conclusion PX and GDX significantly aggravate neurotoxicity of 6-OHDA.And GDX is greater than PX,while PX ＋ GDX is strongest.