Effect of oestrogen on myofibre size and myosin expression in growing rats
Effect of oestrogen on myofibre size and myosin expression in growing rats
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DOI：
10.1113/expphysiol.2004.028373
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发表时间：
2005-01-01
影响因子：
2.7
通讯作者：
McCormick, KM
中科院分区：
文献类型：
--
作者：
Piccone, CM;Brazeau, GA;McCormick, KM
本研究探讨了雌激素剥夺和替代对大鼠跖肌大小和肌球蛋白重链（MHC）亚型组成的影响，在一个时期的生理增长。将7周龄雌性Sprague-Dawley大鼠分配至三个处理组之一：（1）对照动物（Sham）;（2）未进行雌激素替代的卵巢切除动物（OVX/ CO）;和（3）进行17 β-雌二醇替代的卵巢切除动物（OVX/E-2）。将OVX/ CO和OVX/E-2动物与假手术动物配对喂养，以排除摄食量和体重增加差异的潜在混杂效应。手术后4周处死大鼠，取出跖肌进行分析。卵巢切除术对肌纤维大小没有影响，但减少了IIx型MHC的相对数量。雌激素替代可以逆转这种情况，这表明IIx型MHC表达的减少是雌激素介导的作用。雌激素替代减少IIb型MHC的表达和快速肌纤维的大小。快速纤维大小和IIb型MHC表达的变化没有看到卵巢切除术，表明这些变化不仅仅是由于雌激素的存在下，卵巢切除，雌激素替代动物。这些结果表明，另一种卵巢激素可能会抵消雌激素对快速纤维大小和IIb型MHC表达的影响在完整的动物。
This study examined the effect of oestrogen deprivation and replacement on plantaris muscle size and myosin heavy chain (MHC) isoform composition in rats during a period of physiological growth. Seven-week-old female Sprague-Dawley rats were assigned to one of the three treatment groups: (1) control animals (Sham); (2) ovariectomized animals without oestrogen replacement (OVX/ CO); and (3) ovariectomized animals with 17beta-oestradiol replacement (OVX/E-2). OVX/ CO and OVX/E-2 animals were pair-fed with Sham animals to rule out the potentially confounding effects of differences in food intake and weight gain. Rats were killed 4 weeks after surgery and the plantaris muscle was removed for analysis. Ovariectomy had no effect on muscle fibre size, but reduced the relative amount of type IIx MHC. This was reversed with oestrogen replacement, suggesting that the reduction in type IIx MHC expression was an oestrogen-mediated effect. Oestrogen replacement reduced type IIb MHC expression and fast muscle fibre size. Changes in fast fibre size and type IIb MHC expression were not seen with ovariectomy, indicating that these changes were not simply due to the presence of oestrogen in the ovariectomized, oestrogen-replaced animals. These results suggest that another ovarian hormone may counteract the effect of oestrogen on fast fibre size and type IIb MHC expression in intact animals.