Sex differences in steroidogenesis in skeletal muscle following a single bout of exercise in rats
Sex differences in steroidogenesis in skeletal muscle following a single bout of exercise in rats
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DOI：
10.1152/japplphysiol.00558.2007
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发表时间：
2008-01-01
影响因子：
3.3
通讯作者：
Mesaki, Noboru
中科院分区：
文献类型：
--
作者：
Aizawa, Katsuji;Iemitsu, Motoyuki;Mesaki, Noboru
性类固醇激素，如睾酮和雌二醇，在骨骼肌力量和质量的发展中起着重要作用。最近，我们证明骨骼肌可以合成性类固醇激素。骨骼肌中基础类固醇生成或急性运动诱导的类固醇生成改变是否存在性别差异尚不清楚。我们研究了在休息和运动后骨骼肌中睾酮、雌二醇和类固醇生成相关酶（如17 β-羟基类固醇脱氢酶（HSD）、3 β-HSD和芳香酶细胞色素P-450（P450 arom））水平的性别差异。本实验观察了10周龄安静大鼠和10周龄运动大鼠腓肠肌的运动情况。基础肌肉睾酮水平男性高于女性，而雌二醇没有性别差异。此外，17 β-HSD、3 β-HSD和P450 arom转录物和蛋白质表达在女性中更高。在急性运动后，雄性和雌性的肌肉中睾酮水平和17 β-HSD表达增加。相比之下，男性运动后肌肉雌二醇水平增加，但女性没有变化。调节雌激素合成的P450 arom的表达在男性急性运动后增加，但在女性运动后减少。因此，一次运动就可以影响骨骼肌中的类固醇生成系统，而且这些变化在性别之间是不同的。急性运动引起的类固醇生成酶的改变可能会增强骨骼肌中局部类固醇的生成。
Sex steroid hormones, such as testosterone and estradiol, play important roles in developing both strength and mass of skeletal muscle. Recently, we demonstrated that skeletal muscle can synthesize sex steroid hormones. Whether there are sex differences in basal steroidogenesis or acute exercise-induced alterations of steroidogenesis in the skeletal muscle is unknown. We examined sex differences in the levels of testosterone, estradiol, and steroidogenesis-related enzymes, such as 17 beta-hydroxysteroid dehydrogenase (HSD), 3 beta-HSD, and aromatase cytochrome P-450 (P450arom), in the skeletal muscle at rest and after exercise. We studied the gastrocnemius muscles of resting rats (10 wk old) and exercised rats (10 wk old, treadmill running, 30 m/min, 30 min). Basal muscular testosterone levels were higher in males than females, whereas estradiol did not differ between sexes. Additionally, 17 beta-HSD, 3 beta-HSD, and P450arom transcript and protein expression were greater in females. After acute exercise, testosterone levels and 17 beta-HSD expression increased in muscle in both sexes. By comparison, muscular estradiol levels increased in males following exercise but were unchanged in females. Expression of P450arom, which regulates estrogen synthesis, increased after acute exercise in males but decreased after exercise in females. Thus a single bout of exercise can influence the steroidogenic system in skeletal muscle, and these alterations differ between sexes. The acute exercise-induced alteration of steroidogenic enzymes may enhance the local steroidogenesis in the skeletal muscle in both sexes.