丰富环境对快速衰老小鼠行为及一氧化氮合成酶表达的影响

Effect of enriched environment on behavior and expression of nitric oxide synthetase in senescence-accelerated mice

目的研究丰富环境对快速衰老小鼠空间学习能力及一氧化氮合成酶(NOS)表达水平的影响。方法 4月龄SAMP8鼠随机分为丰富环境组(EE)和标准组(SE),通过Morris水迷宫、开场试验观察小鼠的学习记忆能力与焦虑因素;应用Westernblot、Real-time PCR对SAMP8海马区一氧化氮合成酶及其mRNA表达水平的检测。结果行为学上EE组与SE组比较,Morris水迷宫试验中EE组的潜伏期及游泳路程减少(均P<0.01),开场试验中的直立次数明显增多(P<0.01),但未发现平均速度、粪便颗粒数、理毛数、穿格数之间差异有统计学意义;分子生物学检测上,丰富环境增加了nNOS及eNOS表达、eNOS的mRNA表达水平(均P<0.01),但iNOS的表达组间差异无统计学意义(P>0.05)。结论在SAMP8加速衰老期,丰富环境可能调节nNOS及eNOS的表达而改变其学习记忆能力。

Objective To study the enriched environment on spatial learning ability and expression of nitric oxide syn‐thetase (NOS) in senescence‐accelerated mice. Methods Four‐month‐old SAMP8 mice were randomly divided into enriched en‐vironment group (EE) and standard environment group(SE). Morris water maze and open‐field tests were applied to assess the learning and memory abilities as well as factors affecting anxiety of SAMP 8 mice .The expressions of NOS and mRNA in hipp‐ocamal region were detected by Westernblotting and Real‐time PCR. Results In terms of behavior ,the mice in EE group had shorter latent period and swimming distance performed in Morris water maze test ,and had obviously more upright times man‐aged in open‐field test ,when compared with SE group (P < 0.01). As for the mean swimming speed ,fecal particle number , grooming number and square‐crossing number ,no significant differences were observed. By the detection of molecular biology , EE group showed higher expressions of eNOS ,nNOS levels and eNOS mRNA (P< 0.01). No statistical difference was veri‐fied between the SE and EE group with respect to the expression of iNOS (P> 0.05). Conclusion In senescence‐accelerated period of SAM P8 ,the enriched environment is likely to enhance the spatial learning and memory abilities with the regulation of nNOS and eNOS function.