大鼠黑质多巴胺能神经元的二型性  

Sexual dimorphisms of dopaminergic neurons in rat substantia nigra

作　　者：马元怡[1] 孔淑珍[1] 杨黎江[1] 孟金兰[1] 吕乐春[1] 何敏[1] 

机构地区：[1]昆明医学院生理教研室,昆明650031

出　　处：《生理学报》2007年第6期753-758,共6页Acta Physiologica Sinica

基　　金：This work was supported by the Natural Science Foundation of Yunnan Province;China(No.2001C0005R).

摘　　要：成年哺乳动物的某些脑区存在性别差异,即(?)型性,但中脑黑质是否存在性分化目前不清楚。本文旨在探讨成年大鼠中脑黑质是否存在(?)型性。将60只成年大鼠分成5组:(1)正常雌鼠对照组;(2)正常雄鼠对照组:(3)去卵巢组:(4)去睾丸组;(5)去卵巢后回补雌激素组,该组大鼠在去卵巢后的第7天开始连续3 d给予生理剂量的雌激素回补。所有大鼠在右侧黑质埋置记录电极,在清醒和安静的生理状态下连续14d记录黑质的P50听觉诱发电位(P50),之后作黑质酪氨酸羟化酶(tyrosine hydroxylase,TH)免疫组织化学染色,检查TH阳性(TH^+)细胞数量和形态变化。结果表明,正常成年雄鼠黑质的TH^+细胞数量较雌鼠少22.47%(P<0.05),P50的T/C值也低34 72%(P<0.01),提示正常成年大鼠黑质在结构和功能上存在(?)型性。与正常雄鼠相比,去睾丸大鼠黑质的TH^+细胞数量、形态和P50的T/C值无显著性变化(P>0.05)。与正常雌鼠相比,去卵巢大鼠黑质TH^+细胞数量减少28.09%(Jp<0.01),P50的T/C值降低30.85%(P<0.01)。在大鼠去卵巢后的短时间内给予3d生理剂量的雌激素,15～20 d后可观察到其黑质TH^+细胞数量、形态和P50的T/C值基本恢复到去卵巢前水平。结果提示,大鼠中脑黑质的多巴胺能神经元在数量、结构和功能活动上存在性别差异;内源性雌激素在维持黑质多巴胺系统完整性及调节其功能活动中起重要作用。There are sex differences in some brain areas in mammalians. Parkinson＇s disease （PD）, caused by the mesencephalic substantia nigra （SN） dopaminergic neuronal loss, displays sexual difference, i.e., the incidence is higher and the symptoms are more intense in males than that in females. However, it has not been known whether sexual dimorphisms exist in the SN. Sixty adult Sprague- Dawley rats were randomly divided into 5 groups： （1） Female intact group （F-INT group）; （2） Male intact group （M-INT group）; （3） Ovariectomized group （OVX group）; （4） Castration group （CAST group）; （5） Ovariectomized ＋ estrogen-replaced group （OVX-E2 group）： The rats received sequentially physiological dose of estrogen for 3 d from the 7th day after ovariectomization. P50 auditory evoked potential （P50） was recorded for 14 d from electrodes inserted in the rat right SN in quiet and awake state. After recording, the brain tissues were dissected and the tyrosine hydroxylase （TH）-expressing neurons in the compact zone of the SN were counted using cal method. The results showed that the number of TH-positive （TH^＋） ceils in the SN of normal male animals was less than that in normal female rats （P〈0.05）, and the TIC ratio of P50 in normal males was significantly less than that in normal females （P〈0.01）, indicating that there exists sexual difference in function and structure in the SN. No differences in the TIC ratio of P50 or the number of TH^＋ ceils were found between M-INT and CAST groups. The TIC ratio of P50 and the number of TH^＋ ceils in the SN in OVX group were reduced significantly compared with those in F-INT group （P〈0.01）. There was no significant difference in the TIC ratio of P50 and the number of TH^＋ ceils in the SN between OVX-E2 and F-INT groups 15-20 d after estrogen replacement, suggesting that estrogen can promote the survival and functional recovery of dopaminergic neurons in the SN. The results suggest that there exist sex-sp

关 键 词：脑的二型性 雌激素 黑质 多巴胺神经元 感觉门控 P50听觉诱发电位 酪氨酸羟化酶 

分 类 号：R742.5[医药卫生—神经病学与精神病学]