玛咖提取物对大鼠运动耐力和血液激素水平的影响

目的 探讨玛咖提取物对运动耐力和血激素水平的影响。方法 采用循环水流自由游泳，给予Wistar大鼠2.0、4.0和8.0 g/（kg·bw）玛咖提取物，连续给药15 d。第16天，采用酶联免疫吸附法（ELISA）检测血去甲肾上腺素（NA）、雌二醇（E₂）、睾酮（T）水平。结果 给予玛咖提取物2.0、4.0和8.0 g/（kg·bw）15 d，下沉前游泳时间和游泳总时间比单纯游泳组分别延长了32.51%、60.04%、106.52%和16.99%、56.50%、101.73%（P<0.01），下沉次数比单纯游泳组分别减少了18.89%、35.89%、58.06%（P<0.01）。大鼠血NA水平比对照组分别增加了3.30%、6.60%、16.50%，比单纯游泳组分别增加了42.49%、47.05%、60.70%；血E₂水平比对照组增加了132.83%、102.72%、62.26%（P<0.01），比单纯游泳组降低了23.88%、33.72%、46.95%；血T水平比对照组分别增加了5.11%、37.65%、123.16%，比单纯游泳组分别增加了28.98%、68.92%、173.85%（P<0.01）。结论 玛咖提取物具有缓减疲劳、增强运动能力的作用。其机制与升高血NA和T水平，降低E₂水平有关。

Effects of maca extract on exercise endurance and blood hormone levels in the rats

Objective To study the effects of maca extract on exercise endurance and blood hormone levels in the rats. Methods Wistar rats treated with maca extract (2.0, 4.0, 8.0 g/kg body weight) were freely swimming in the circulating water flow daily for 15 days. On the 16th day of experiment, the exercise endurance and blood noradrenaline (NA), estradiol (E2), and testosterone (T) levels of the rats were determined.Results The rats administered with maca extract at the doses of 2.0, 4.0, 8.0 g/kg body weight for 15 d showed that the swimming time before sinking was increased by 32.51%, 60.04%, 106.52%, the total swimming time was extended by 16.99%, 56.50%, and 101.73% respectively (P<0.01); while the number of sinking was decreased by 18.89%, 35.89%, and 58.06%, respectively (P< 0.01), compared with those swimming rats without maca extract treatment. The noradrenaline level in the blood of rats treated with maca extract 2.0, 4.0, 8.0 g/kg body weight was increased by 3.30%, 6.60%, and 16.50%, respectively, compared with the control group, and increased by 42.49%,47.05%, and 60.70%, respectively, compared with the swimming rats without extract treatment; the E₂ level was increased by 132.83%,102.72%, and 62.26% (P<0.01)respectively, compared with the control group, while decreased by 23.88%, 33.72%, and 46.95% (P<0.01) respectively, compared with the swimming rats without extract treatment. The blood testosterone level was increased by 5.11%, 37.65%, and 123.16% (P<0.01) respectively, compared with the control group, and increased by 28.98%, 68.92%, and 173.85%, (P<0.01) respectively, compared with the swimming rats without extract treatment.Conclusions The results of this study demonstrate that maca extract has effect to resist fatigue and enhance exercise capacity in rats. The mechanism is associated with reduced blood E₂, and increased noradrenaline and testosterone levels in the blood of rats.