熟地黄对去势大鼠海马神经元凋亡的抑制作用

目的探讨熟地黄对卵巢去势大鼠海马神经元凋亡的保护作用。方法取SD雌性大鼠,行双侧卵巢切除术以建立去势动物模型;采用Morris水迷宫测试系统检测大鼠学习记忆功能;用放射免疫法检测血清雌二醇(E2)水平;Westernblot及激酶活性测定法检测海马内半胱天冬氨酸蛋白酶-3(Caspase-3)的表达和活性,琼脂糖凝胶电泳观察海马神经元凋亡;于卵巢切除4周后以熟地黄84、g/(kg.d)对去势大鼠连续灌胃6周进行治疗,观察其干预效果。结果经行为学检测发现卵巢去势大鼠学习记忆功能明显减退;血清E2水平显著下降;海马内Caspase-3含量和活性明显增高,细胞核DNA降解;使用熟地黄灌胃治疗后并不能明显改善去势大鼠血清E2水平,但能显著改善大鼠学习记忆功能和降低海马内Caspase-3的含量和活性,抑制细胞核DNA降解。结论卵巢切除可导致雌性大鼠海马神经元凋亡,熟地黄对雌激素缺乏所致的学习记忆障碍和海马神经元凋亡具有保护作用,但并不是通过改变雌激素的水平来实现的。

Effect of Prepared Radix Rehmanniae on Apoptosis of Hippocampcal Neurons in Ovariectomized Rats

Objective To investigate the protective effect of prepared Radix Rehmanniae(PRR) on the apoptosis of hippocampcal neurons in ovariectomized rats.Methods Female Sprague-Dawley rats were bilaterally ovariectomized to establish an animal model.Morris water maze tests were used for behavioral study.The level of serum estradiol was measured by using radioimmunoassay.Western blot and kinase activity assays were used to determine the expression and activity of Caspase-3 in the hippocampus.The hippocampal neuronal apoptosis was observed by DNA electrophoresis.The ovariectomized rats were treated with PRR 4 weeks after overiectomy at a high or low dose for 6 consecutive weeks.Results Overiectomy induced a marked learning and memory dysfunction in Morris water maze tests and reduction in level of serum estradiol.Apoptotic changes were detected in the hippocampus of ovariectomized rats,such as the increases of the concentration and activity of Caspase-3,nucleus degeneration.After treatment with PRR ,the impaired learning and memory were improved,the concentration and activity of Caspase-3 of hippocampus decreased,and the nucleus degeneration was inhibited,but the level of serum estradiol wasn't significantly increased.Conclusion Overiectomy could induce hippocampal neuronal apoptosis of female rats.PRR could remarkably ameliorate the impaired learning and memory,and the hippocampal neuronal apoptosis caused by lack of estrogen.Its mechanism was not based on increasing the level of estradiol.