美满霉素对阿尔茨海默病大鼠认知损伤及海马 BDNF、 Bcl-2 和 Bax 表达的影响

目的 观察美满霉素对阿尔茨海默病（AD）大鼠认知功能和海马脑源性神经营养因子（BDNF）、凋亡相关因子 Bcl-2 和 Bax 表达的影响， 探讨美满霉素对 AD 大鼠脑保护作用的机制。 方法 侧脑室注射 Aβ25-35 建立 AD 大鼠模型。 30 只健康雄性 SD 大鼠随机分成对照组、模型组和治疗组， 每组 10 只。 对照组和模型组腹腔内注射生理盐水 1 mL/（kg· d）， 治疗组腹腔注射美满霉素 50 mg/（kg· d）， 均持续 14 d。 Morris 水迷宫检测行为学变化， 蛋白免疫印迹（Western blotting）法和酶联免疫吸附试验（ELISA）法检测海马 BDNF、Bcl-2 和 Bax 蛋白的表达， 原位末端标记（TUNEL）法检测海马神经元凋亡率。 结果 美满霉素可以明显提高 AD 大鼠学习记忆能力， 上调 AD 大鼠海马 BDNF、Bcl-2 表达， 下调 Bax 表达， 减少海马神经元凋亡。 结论 美满美素可以通过促进神经元的生长、抑制神经元的凋亡发挥脑保护作用。

Effects of minocycline on the cognition and expression of BDNF,Bcl-2 and Bax in hippocampus of Alzheimer’ s disease model rats

Objective To investigate the effect of minocycline on the cognition and expressions of brain- derived neurotrophic factor (BDNF), apoptosis related factor Bcl-2 and Bax in hippocampus of rats with Alzheimer’ s disease (AD).Methods The rat model was established by microinjection of Aβ25-35 into lateral ventricle. Thirty healthy male SD rats were randomly divided into three groups: control group, model group and minocycline treatment group. Normal saline 1 mL/(kg· d) was intraperitoneally injected in control group and model group. The minocycline treatment group was intraperitoneally injected with minocycline 50 mg/(kg· d) for 14 days. Morris water maze was used to detect the behaviors of animals. The expressions of BDNF, Bcl-2 and Bax in hippocampus were measured by Western blotting and enzyme linked immunosorbent assay (ELISA). The apoptosis of neurons was detected by TdT- mediated dUTP nick- end labeling (TUNEL). Results Minocycline greatly improved the behaviors of AD rats, up- regulated the expressions of BDNF and Bcl- 2, and downregulated the expression of Bax in hippocampus, and reduced cell apoptosis. Conclusion Minocycline plays a protective role in neural function by promoting the growth of neurons and inhibiting the neuronal apoptosis.