目的 研究小檗碱对AD大鼠模型胰岛素降解酶(IDE)表达的影响.方法 18只SD大鼠采用完全随机数字表法分为正常组、模型组和小檗碱组,每组6只.正常组不做任何处理,模型组及小檗碱组大鼠通过双侧海马立体定向注射凝聚态Aβ1-40(5 μg)建立AD模型.小檗碱组造模后灌胃给予盐酸小檗碱50mg/kg,1次/d,共14d.采用实时荧光定量PCR法和Western blotting法观察小檗碱对IDE表达的影响.结果 小檗碱组大鼠IDE mRNA的相对拷贝数(45.70±12.80)较正常组(23.40±11.30)及模型组(34.20±6.70)明显增加,小檗碱组大鼠海马IDE蛋白相对表达量(0.61±0.05)较正常组(0.23±0.03)及模型组(0.46±0.07)明显增加,差异均有统计学意义(P<0.05).结论 大鼠海马立体定向注射凝聚态Aβ1-40可以导致海马部位IDE表达增加,小檗碱可以通过促进IDE的表达而促进Aβ的清除.
Objective To explore the effect of berberine chloride on the expression of insulin degrading enzyme (IDE) in the rat models with Alzheimer's disease (AD). Methods Eighteen adult male SD rats, weighting 220-250 g, were randomly divided into normal control group, Aβ1-40 group and Aβ40+berberine chloride group (n=6). The rat models with AD were established by stereotactically injecting condensed Aβ1-40 (5 μg) into the bilateral hippocampus of rats. The rats in the Aβ1-40+berberine chloride group were given berberine chloride (50 mg/kg) by intragastric administration once daily for 14 d. The expressions of IDE were assayed by real time polymerase chain reaction (real-time PCR) and Western blotting. Results The relative quantity of mRNA expression of IDE was (34.2±6.7) in the Aβ1-40+berberine group, which was significantly increased as compared with that in the Aβ1-40 group (45.7±12.8) and normal control group (23.4±11.3, P〈0.05). The relative quantity of protein expression of IDE was (0.61 ±0.05) in the Aββ1-40+berberine group, which was significantly increased as compared with that in the Aβ1-40group (0.46±0.07) and the normal control group (0.23±0.03, P〈0.05). Conclusion The injection of Aβ1-40 (5 μg) in the hippocampus can highly increase the expressions of IDE, thus resulting in the increase effect of Aβ clearance.