O'Connor Jennifer L, McBrayer Lance D, Higham Timothy E, Husak Jerry F, Moore Ignacio T, Rostal David C
Georgia Southern University, Statesboro, Georgia 30460, USA.
Physiol Biochem Zool. 2011 Jul-Aug;84(4):394-405. doi: 10.1086/660850.
Testosterone (T) is thought to affect a variety of traits important for fitness, including coloration, the size of sexual ornaments, aggression, and locomotor performance. Here, we investigated the effects of experimentally elevated T and locomotor training on muscle physiology and running performance in a nonterritorial male lizard species (Aspidoscelis sexlineata). Additionally, several morphological attributes were quantified to examine other characters that are likely affected by T and/or a training regimen. Neither training alone nor training with T supplementation resulted in increased locomotor performance. Instead, we found that T and training resulted in a decrease in each of three locomotor performance variables as well as in hematocrit, ventral coloration, and testis size. Strikingly, neither the size nor the fiber composition of the iliofibularis or gastrocnemius muscles was different among the two treatments or a group of untrained control animals. Hence, the relationships among T, training, and associated characters are not clear. Our results offer important insights for those hoping to conduct laboratory manipulations on nonmodel organisms and highlight the challenges of studying both training effects and the effects of steroid hormones on locomotor performance.
睾酮（T）被认为会影响多种对适应性很重要的特征，包括体色、性饰的大小、攻击性和运动表现。在此，我们研究了实验性提高的T水平和运动训练对一种非领地性雄性蜥蜴物种（四线侧斑南美蜥）肌肉生理学和奔跑表现的影响。此外，还对几个形态学特征进行了量化，以检查其他可能受T和/或训练方案影响的特征。单独训练或补充T训练均未导致运动表现提高。相反，我们发现T和训练导致三个运动表现变量以及血细胞比容、腹部体色和睾丸大小均下降。令人惊讶的是，在两种处理组或一组未训练的对照动物中，髂腓肌或腓肠肌的大小和纤维组成均无差异。因此，T、训练和相关特征之间的关系尚不清楚。我们的结果为那些希望对非模式生物进行实验室操作的人提供了重要见解，并突出了研究训练效果和类固醇激素对运动表现影响的挑战。
