银杏叶提取物对训练大鼠不同类型肌纤维抗氧化活性的影响

目的研究银杏叶提取物(GBE)对训练大鼠不同类型肌纤维自由基代谢的影响,探讨其抗运动性疲劳机制。方法SD大鼠随机分成训练组和GBE训练组,GBE训练组按100mg/kg·d灌胃GBE悬液。训练3w后,进行力竭性运动,测定力竭运动前、力竭后即刻、24h、48h股四头肌白肌、红肌、混合肌MDA含量、T-SOD和GSH-Px活性。结果GBE使训练大鼠白肌MDA含量增加49.69%(P<0.05),红肌降低55.23%(P<0.001),混合肌降低38.07%(P<0.005),使训练大鼠运动力竭后即刻、24h、48h白肌MDA含量分别增加106.2%(P<0.005)、87.82%(P<0.005)和33.09%(P<0.05),使力竭后24h红肌MDA含量增加60.00%(P<0.05),使力竭后即刻、24h、48h混合肌MDA含量均增加(分别为P<0.05、P<0.05、P=0.056)。GBE使训练大鼠白肌T-SOD活性增强38.10%(P<0.005),混合肌增强19.58%(P<0.05),使训练大鼠运动力竭后即刻、24h白肌SOD活性分别增强40.63%、25.56%(均为P<0.005),使力竭后24h时红肌明显增强(P<0.05),力竭后即刻和24h时混合肌明显增强(分别为P<0.05、P<0.005)。GBE使训练大鼠白肌GSH-Px活性增强115.8%(P<0.001),红肌增强37.26%(P<0.05),混合肌增强70.44%(P<0.005),使训练大鼠运动力竭后即刻和24h时白肌GSH-Px活性分别增强75.55%(P<0.005)和34.07%(P<0.05),力竭后即刻和24h时红肌减弱(分别为P=0.072和P=0.063),力竭后即刻混合肌明显增强(P<0.05)。结论GBE主要促进训练大鼠红肌脂质过氧化物清除,增强白肌代谢和抗氧化酶活性,从而提高训练效果,延迟大强度运动疲劳的发生。

EFFECTS OF GINKGO BILOBA EXTRACT ON FREE RADICAL METABOLISM OF DIFFERENT FIBER TYPES OF QUADRlCEPS IN EXERCISED RATS

Objective To study the effects of Ginkgo biloba extract(GBE)on free radical metabolism of different fiber types of quadficeps in exercised rats and its mechanism.Method Increasing load exercised rat and the controls with water.The levels of malondialdehyde(MDA)and the activities of total superoxide dismutase(T-SOD),glutathione peroxidase(GSH-Px)of red muscle,white muscle and whole quadriceps of exercised rats were examined before exhaustive exercise,at instant,24h and 48h after strenuous exhaustive exercise.Results Compared with the controls,MDA contents were 49.69%higher in white muscle(P<0.05),55.23%lower in red muscle(P<0.00 1)and 38.07%lower in whole quadriceps(P＜0.005),106.2%higher at instant (P<0.005),87.82%higher at 24h(P<0.005),33.09%higher at 48h(P<0.05)in white muscle,60.00%higher at 24h(P<0.05)in red muscle and higher at instant,24h,48h(P<0.05)in whole quadficeps after exhaustive exercise in GBE group.T-SOD activities were 38.10%stronger in white muscle (P<0.005),19.58%stronger in whole quadficeps(P<0.05),40.64%stronger at instant(P<0.005),25.56%stronger at 24h(P<0.005)in white muscle,stronger at 24h(P<0.05)in red muscle,stronger at instant(P<0.05),and at 24h(P<0.005)in whole quadficepsafter exhaustive exercise in GBE group.GSH-Px activities were 115.8%stronger in white muscle(P<0.001),37.26%stronger in red muscle(P<0.05)and 70.44%stronger in whole quadficeps(P<0.005),75.55%stronger atinstant(P<0.005),34.07%stronger at 24h(P<0.05)in white muscle,tendentiously weaker at instant(P=072)and at 24h(P=0.063)in red muscle and stronger at instant(P<0.05)in whole quadficeps after exhaustive exercise in GBE group.Conclusion GBE execs anti-exercise fatigue and improves exercise performance mainly owing to cleaning free radicals in red muscle and inducing increase of antioxidases activities in white muscle.