Acute severe male hypo-testosteronemia affects central motor command in humans
Acute severe male hypo-testosteronemia affects central motor command in humans
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DOI：
10.1016/j.jelekin.2015.12.004
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发表时间：
2016-06-01
影响因子：
2.5
通讯作者：
Di Luigi, Luigi
中科院分区：
文献类型：
--
作者：
Felici, Francesco;Bazzucchi, Ilenia;Di Luigi, Luigi
目的：为了间接评估雄激素对人类神经肌肉系统的影响，我们分析了诱导的短期性腺功能减退状态（血清总睾酮-TT < 2.3 ng/ml）是否可能影响骨骼肌和/或肌肉神经机械性能的中枢驱动。研究方法：我们比较了9名性腺功能减退男性志愿者（Hypo）和10名健康对照者（Cont）肱二头肌的自愿和电诱发肌肉sEMG信号。测定血清TT和双氢睾酮（DHT）。结果如下：相对于Hypo，Cont在任何角速度下均表现出显著更高的中值频率含量（kHz）;归一化的kHz [95.9%]（SD = 23.3）vs 73.8%（SD = 9.3）];肌纤维传导速度（CV）从最低到最高角速度;疲劳试验时的初始频率[91.78 Hz（SD = 22.03）vs 70.94 Hz（SD = 11.06）]以及标准化斜率[-0.64（SD = 0.14 vs -0.5（SD = 0.11）]。在非疲劳状态下，Hypo显示出较慢的单次抽搐达到峰值时间（TTP）。在Cont中，疲劳后半松弛时间（HRT）减少，而Hypo增加（组间p < 0.05）。TT和双氢睾酮与收缩压和CV之间的显著相关性仅在自主收缩期间发现。结论：雄性动物短暂暴露于极低的血清TT浓度似乎决定了NM系统的兴奋性降低，反过来，这将有利于主要招募慢收缩MU。（C）2015 Elsevier Ltd.保留所有权利。
Purpose: To indirectly evaluate the effect of androgens on neuromuscular system in humans we analyzed if an induced short-term hypogonadal state (serum total testosterone-TT < 2.3 ng/ml) may affect central drive to skeletal muscle and/or muscle neuro-mechanical performance. Methods: We compared voluntary and electrically evoked muscle sEMG signals from biceps brachii in nine hypogonadal male volunteers (Hypo) and in ten healthy controls (Cont). Serum TT and dihydrotestosterone (DHT) were assayed. Results: With respect to Hypo, Cont exhibited significantly higher median frequency content (MDF) at any angular velocity; normalized MDF [95.9% (SD = 23.3) vs 73.8% (SD = 9.3)]; muscle fiber conduction velocity (CV) from lowest to highest angular velocities; initial MDF at fatigue test [91.78 Hz (SD = 22.03) vs 70.94 Hz (SD = 11.06)] as well as was the normalized slope [-0.64 (SD = 0.14 vs -0.5 (SD = 0.11)]. In the non-fatigued state, Hypo showed a slower single twitches time to peak (TTP). In Cont, half relaxation time (HRT) decreased after fatigue while increased in Hypo (p < 0.05 between groups). A significant correlation between both TT and dihydrotestosterone with MDF and CV was found during voluntary contractions only. Conclusions: A brief exposure to very low serum TT concentration in males seem to determine a reduced excitability of the NM system which, in turn, would favor a predominant recruitment of slow twitch MUs. (C) 2015 Elsevier Ltd. All rights reserved.