Day J R, Laping N J, Lampert-Etchells M, Brown S A, O'Callaghan J P, McNeill T H, Finch C E
Andrus Gerontology Center, University of Southern California, Los Angeles 90089-0191.
Neuroscience. 1993 Jul;55(2):435-43. doi: 10.1016/0306-4522(93)90512-e.
This study demonstrates that gonadal steroids (estradiol, testosterone, dihydrotestosterone) can regulate the expression of glial fibrillary acidic protein in the adult male rat brain. Previously, we showed that castration of adult male rats increased glial fibrillary acidic protein messenger RNA in the hippocampus and that this increase was additive with the increase induced by deafferenting entorhinal cortex lesions [Day et al. (1990) Molec. Endocr. 4, 1995-2002 . We extended these effects of castration and entorhinal cortex lesion to glial fibrillary acidic protein, using immunoassays. Furthermore, we found regional differences in responses to castration and inhibited by sex steroids. In contrast, hypothalamic glial fibrillary acidic protein expression was inhibited by castration. Similar regional differences were also shown for astrocyte glial fibrillary acidic protein distribution by immunocytochemistry. The regional specificity of glial fibrillary acidic protein expression after castration and sex steroid replacement is pertinent to the role of astrocytes in synaptic plasticity in unlesioned adults as well as in responses to lesions where the steroid milieu has been shown to influence sprouting.
本研究表明，性腺类固醇（雌二醇、睾酮、二氢睾酮）可调节成年雄性大鼠脑中胶质纤维酸性蛋白的表达。此前，我们发现成年雄性大鼠去势会增加海马体中胶质纤维酸性蛋白信使核糖核酸的含量，且这种增加与去传入性内嗅皮质损伤所诱导的增加具有累加性[戴伊等人（1990年），《分子内分泌学》4，1995 - 2002页]。我们利用免疫测定法，将去势和内嗅皮质损伤的这些作用扩展至胶质纤维酸性蛋白。此外，我们发现对去势的反应存在区域差异，且受性类固醇抑制。相比之下，下丘脑胶质纤维酸性蛋白的表达受到去势抑制。通过免疫细胞化学法也显示，星形胶质细胞胶质纤维酸性蛋白分布存在类似的区域差异。去势和性类固醇替代后胶质纤维酸性蛋白表达的区域特异性，与星形胶质细胞在未受损成年个体突触可塑性中的作用以及在对损伤的反应中的作用相关，在损伤反应中，类固醇环境已被证明会影响发芽。
