雌激素对去卵巢大鼠小脑皮质内脑源性神经营养因子及神经肽Y表达的影响

目的探讨雌激素对大鼠小脑皮质内脑源性神经营养因子(BDNF)、神经肽Y(NPY)表达水平的影响。方法成年雌性大鼠分为3组:正常对照组(INT组),去卵巢组(OVX组)及雌激素处理组(E组)。用放射免疫分析方法检测血中雌二醇含量,运用免疫组织化学方法检测小脑皮质内BDNF、NPY的表达水平。结果去卵巢大鼠体内雌激素水平与对照组比较明显降低(P<0.001);BDNF免疫阳性反应物分布于小脑皮质的蒲肯野氏细胞层,分子层及颗粒细胞层可见散在阳性细胞。NPY阳性产物主要定位于蒲肯野细胞中。去卵巢大鼠小脑皮质BDNF、NPY的表达强度及阳性细胞数量较对照组明显降低(P<0.001),E组较OVX组阳性产物的强度和阳性细胞数目明显回升(P<0.001),但仍低于对照组。结论雌激素可促进大鼠小脑皮质内BDNF、NPY的表达,在维持和保护小脑神经元的结构和功能中发挥重要作用。

Effects of Estrogen on Brain Derived Neurotrophic Factor and Neuropeptide Y Levels in Cerebellar Cortex of Ovariectomized Rats

Objective To investigate the effects of estrogen on brain derived neurotrophic factor (BDNF) and neuropeptide Y (NPY) levels in cerebellar cortex of ovariectomized rats. Methods 24 female Wistar rats were randomly divided into three groups: intact (INT) group, ovariectomized (OVX) group, and OVX+estrogen 0.5 mg/kg every day group (E group). Radioimmunoassay (RIA) was used to measure the estrogen content in plasma, and the levels of BDNF and NPY were measured with Immunohistochemistry. Results Compared with the INT group, the plasma estrogen level significantly reduced in OVX group (P<0.001). However, the plasma estrogen level was higher in the E group than that in the OVX group (P<0.001). The BDNF and NPY presented in the Purkinje cell layer,and BDNF also distributed in the molecular layer and granular layer. Compared with that in the INT group, BDNF and NPY positive cells markedly decreased in OVX group, with slight cytosol staining in the cerebellar cortex (P<0.001). The BDNF and NPY positive neurons increased in E group compared with that in the OVX group (P<0.001). Conclusion Estrogen can increase the BDNF and NPY levels in cerebellar cortex of female rats, which may protect the structure and function of cerebellar neurons.