5α-双氢睾酮对大脑皮质组织结构和细胞凋亡的影响

Effects of 5α-DHT on tissue structure and cell apoptosis of cerebral cortex

采用免疫组织化学、Western blot等方法,研究了5α-双氢睾酮对大脑皮质组织结构和细胞凋亡的影响。结果显示:(1)去睾丸引起大脑皮质神经元数量下降,细胞凋亡数量增加,部分神经元线粒体、内质网肿胀,出现凋亡小体,髓鞘板层疏松、分离并脱髓鞘,雄激素受体、Bcl-2表达下降,GFAP、BAX表达增加,与正常组、假手术组和去睾丸后补充5α-双氢睾酮组比较,均呈显著性差异(P<0.05);(2)与去睾丸组比较,去睾丸后补充5α-双氢睾酮引起神经元数量增加,细胞凋亡数量减少,神经元线粒体、内质网等细胞器结构正常,雄激素受体、Bcl-2表达增加,胶质纤维酸性蛋白、BAX表达下降,且均呈显著性差异(P<0.05);(3)正常组、假手术组和去睾丸后补充5α-双氢睾酮组之间,以上各试验观察指标均无显著性差异(P>0.05)。结果表明,5α-双氢睾酮可通过与雄激素受体结合,促进Bcl-2表达,抑制胶质纤维酸性蛋白、BAX表达,维持神经元、胶质细胞正常的超微结构,阻止细胞凋亡,保持神经元数量正常,实现对大脑皮质的保护。

To explore the protective mechanisms of androgen on brain,an animal model of castrated rats was used to study the effects of 5α-DHT on tissue structure and cell apoptosis in cerebral cortex by means of immunohistochemistry,western blot,et al.The results showed were as follow:(1)The removal of testes caused number of cortical neurons significantly decreased,apoptosis cells markedly increased,mitochondria and endoplasmic reticulum swelled,apoptosis bodies appeared,myelin plate layer loosed,isolated and demyelinated,the expression of androgen receptor and Bcl-2decreased,while GFAP,BAX expression markedly rose.Compared with NC group,IMC group and GM+T group,there were significant differences in the above indexes(P<0.05);(2)In comparion with GM group,in GM+T group,5α-DHT induced a significant increase in the number of neurons and a reduction in the apoptotic cells,kept the structure of neuronal mitochondria,endoplasmic reticulum and other organelles normal,made the expression of androgen receptor and Bcl-2rise and GFAP,BAX expression markedly decrease,there were also significant differences in the above indexes(P<0.05);(3)Among NC group,IMC group and GM+T group,there were no significant differences in the above indexes(P>0.05).The results suggust that 5α-DHT may achieve the protection of cerebral cortex by combining with androgen receptor to promote Bcl-2and inhibit GFAP,BAX expression,maintaining normal ultrastructure,preventing apoptosis and thus keeping the number of neurons normal.