Paquette Amélie, Wang Dongaho, Gauthier Marie-Soleil, Prud'homme Denis, Jankowski Marek, Gutkowska Jolanta, Lavoie Jean-Marc
Département de kinésiologie, Université de Montréal, C.P. 6128, Succ. centre-ville, Montreal, QC, Canada H3C 3J7.
Mol Cell Biochem. 2007 Dec;306(1-2):179-87. doi: 10.1007/s11010-007-9568-5. Epub 2007 Aug 1.
Estrogens exert their biological roles mainly through estrogen receptors (ER) that function as ligand-activated transcription factors. ER content in a cell is regulated by many factors and is decisive for estrogen action. The purpose of the present study was to investigate the influence of an 8-wk endurance training program on ER expression in the liver, right atrium (RA), and left ventricle (LV) of intact and ovariectomized (Ovx) rats. We measured ERalpha and ERbeta mRNA content by reverse transcription-polymerase chain reaction (RT-PCR). We found an important increase in ERalpha mRNA levels in the liver (300%; P < 0.01) and in ERbeta mRNA levels in the RA (200%; P < 0.05), and a marked decrease in ERalpha (80%; P < 0.01) and ERbeta (40%; P < 0.05) transcripts content in the LV of intact rats after endurance training. On the other hand, ERalpha mRNA levels were depressed by 50% (P < 0.01) in the liver, and increased by 60% (P < 0.01) in LV of Ovx rats after exercise training. These results first indicate that endurance training is associated with modifications of ER transcripts levels in the liver, LV, and RA of female rats. More specifically, these effects are tissue and isoform-specific and the direction of the response (increase or decrease) is different in intact and Ovx rats. It is suggested that some of the adaptations to endurance training in liver and heart may be mediated by an ER-dependent mechanism.
雌激素主要通过作为配体激活转录因子发挥作用的雌激素受体（ER）来行使其生物学功能。细胞中的ER含量受多种因素调节，对雌激素作用起决定性作用。本研究的目的是调查为期8周的耐力训练计划对完整和去卵巢（Ovx）大鼠肝脏、右心房（RA）和左心室（LV）中ER表达的影响。我们通过逆转录-聚合酶链反应（RT-PCR）测量了ERα和ERβ mRNA含量。我们发现，耐力训练后，完整大鼠肝脏中ERα mRNA水平显著升高（300%；P<0.01），RA中ERβ mRNA水平升高（200%；P<0.05），而LV中ERα（80%；P<0.01）和ERβ（40%；P<0.05）转录本含量显著降低。另一方面，运动训练后，Ovx大鼠肝脏中ERα mRNA水平降低了50%（P<0.01），LV中升高了60%（P<0.01）。这些结果首次表明，耐力训练与雌性大鼠肝脏、LV和RA中ER转录本水平的改变有关。更具体地说，这些影响具有组织和异构体特异性，完整和Ovx大鼠的反应方向（增加或减少）不同。提示肝脏和心脏对耐力训练的一些适应性变化可能由ER依赖性机制介导。
