Relationship among anabolic androgenic steroid, weight-lifting exercise and physiological functions.

测定了一种合成代谢雄激素类固醇（AAS）对大鼠后肢骨骼肌单次力竭举重后胸苷和氨基酸摄取的影响。类固醇组在实验前一周给予癸酸诺龙或油载体。血清肌酸激酶（CK）活性，用来衡量肌肉损伤，在运动后30和60分钟两组增加。与对照组相比，类固醇组的总重量增加，而CK水平降低。两组的胸苷摄取（细胞有丝分裂活性）在运动后两天达到峰值，对照组比类固醇大鼠高90%，反映出更高水平的肌肉损伤。在休息时，类固醇组的亮氨酸摄取（氨基酸代谢）比对照组高80%，运动后恢复快33%。测定了足底肌的原位等长力学性能。唯一显著的区别是，与对照组相比，他们的抗疲劳能力更高。这些结果表明，AAS处理1)改善了CK外排和肌纤维损伤，提高了蛋白质合成速度；2)提高了初级跖屈肌的体内工作能力和原位抗疲劳能力。为了确定AAS诱导攻击性行为和工作能力增加的可能机制，在选定的大脑区域测量了一些生物胺的水平。类固醇组下丘脑的去甲肾上腺素及其代谢物MHPG（4-羟基-3-甲氧基苯基乙二醇）水平比对照组和对照组增加了2-和7倍。类固醇组血清素及其代谢物5-HIAA（5-羟基吲哚-3-乙酸）的水平比对照组和对照组高- 40%和-50%。与对照组和对照组相比，类固醇组脑室周围区表达c-fos的神经元数量显著增加，表明癸酸诺龙治疗后神经元活性增强，合成代谢雄激素类固醇治疗后身体机能增强。与下丘脑肾上腺素能和血清素能胺水平升高的解释一致，这可能有助于攻击性行为以及改善身体表现。少

The influence of an anabolic androgenic steroid (AAS) on thymidine and amino acid uptake in rat hindlimb skeletal muscles after a single exhaustive bout of weight-lifting was determined. Nandrolone decanoate or oil vehicle was administered to the Steroid group one week prior to the experiments. Serum creatine kinase (CK) activity, used as a measure of muscle damage, increased 30 and 60 min after exercise in both groups. The total amount of weight lifted was higher, whereas CK levels were lower in Steroid than Control rats. Thymidine uptake (cellular mitotic activity) peaked two days after exercise in both groups and was 90% higher in Control than Steroid rats, reflecting a higher level of muscle damage. Leucine uptake (amino-acid metabolism) was ~80% higher at rest and recovered 33% faster post-exercise in Steroid than Control rats. The in situ isometric mechanical properties of the plantaris muscle were determined. The only significant difference was a higher fatigue resistance in the … More Steroid compared to the Control group. These results indicate that AAS treatment 1) ameliorates CK efflux and muscle fiber damages and enhances the rate of protein synthesis and 2) enhances in vivo work capacity and the in situ fatigue resistance of a primary plantarflexor muscle. To identify possible mechanisms for AAS induced increase in aggressive behavior and work capacity, the levels of some biogenic amines were measured in selected regions of the brain. The levels of norepinephrine and its metabolite MHPG (4-hydroxy-3- methoxyphenylglycol) were increased by -2- and -7-fold in the hypothalamus of the Steroid compared to the Control and Vehicle groups. The levels of serotonin and its metabolite 5-HIAA (5-hydroxy-indole-3-acetic acid) were -40 and -50% higher in the Steroid compared to the Control and Vehicle groups. A significantly higher number of c-fos expressing neurons were observed in the periventricular region of the Steroid than the Control and Vehicle groups, indicating enhanced neuronal activity following nandrolone decanoate treatment Combined, the physical performance enhancement following anabolic-androgenic steroid treatment, are consistent with the interpretation that elevated levels of adrenergic and serotonergic amines in the hypothalamus could contribute to aggressive behaviors as well as improved physical performance. Less