葛根素对运动疲劳大鼠海马NO-cGMP信号系统的影响

目的：研究葛根素对运动疲劳大鼠认知能力和海马组织NO-cGMP信号系统的影响。方法：选取成年雄性SD大鼠30只。将大鼠随机分为3组：安静对照组、运动对照组、运动加药组，每组10只大鼠。对大鼠进行为期10d递增负荷游泳，测试大鼠认知能力和海马iNOS mRNA、nNOS mRNA表达和cGMP、NO含量。结果：运动对照组大鼠中心区停留时间百分比、通过原平台位置次数和nNOS mRNA含量较安静对照组显著下降，大鼠海马NO含量、cGMP含量、iNOS mRNA表达显著增加；运动加药组大鼠中心区停留时间百分比、通过原平台位置次数和nNOS mRNA表达较运动对照组显著增加。大鼠海马组织NO含量、iNOS mRNA表达、cGMP含量较运动对照组显著降低。结论：葛根素能显著降低运动疲劳大鼠海马组织的NO含量，其结果可能与iNOS mRNA表达的降低有关，并可能通过降低海马组织NO含量，使运动疲劳大鼠海马cGMP含量趋于稳定以实现运动疲劳大鼠的神经保护功能。

Influence of Puerarin Administration on Hippocampal NO-cGMP Signaling System in Rats with Exercise-Induced Fatigue

Objective: To investigate the effect of puerarin on cognitive ability and hippocampal tissue NO-cGMP signaling in rats with exercise induced fatigue. Methods: A total of 30 adult male SD rats were randomly assigned to 3 groups (10 rats in each group): no exercise control, exercise and exercise plus puerarin groups. The rats in both exercise groups were subjected to increasing weight-loading swimming training for 10 d. The cognitive ability of rats was evaluated by morris water maze test, and the hippocampal iNOS mRNA and nNOS mRNA expression levels and cGMP and NO contents were measured. Results: The exercise control group showed a significant decrease in percent residence time in the central area, the number of original platform passes, and hippocampal nNOS mRNA expression level but a significant increase in hippocampal cGMP and NO contents and iNOS mRNA expression level as compared to the no exercise control. The percent residence time in the central area, the number of original platform passes and nNOS mRNA expression level of the exercise plus puerarin group were significantly higher than those of the exercise control group, whereas the hippocampal cGMP and NO contents and iNOS mRNA expression lelvel of the exercise plus puerarin group were significantly lower than those of the exercise control group. Conclusion: Puerarin administration can result in a marked decrease in hippocampal NO content in rats with exercise induced fatigue, which may be related to the decreased expression of iNOS mRNA. Moreover, puerarin has some neuroprotective effect on rats with exercise induced fatigue by inhibiting hippocampal NO and stabilizing cGMP production.