Effects of ovariectomy and estrogen on skeletal muscle function in growing rats
Effects of ovariectomy and estrogen on skeletal muscle function in growing rats
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DOI：
10.1023/b:jure.0000021398.78327.39
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发表时间：
2004-01-01
影响因子：
2.7
通讯作者：
Brazeau, GA
中科院分区：
文献类型：
--
作者：
McCormick, KM;Burns, KL;Brazeau, GA
本研究探讨了雌激素替代对生理生长期去卵巢大鼠比目鱼肌大小和收缩功能的影响。将7周龄雌性Sprague-Dawley大鼠分配到三个处理组之一：（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/E2）。将OVX/CO和OVX/E2动物与假手术动物配对喂养，以排除食物摄入差异的潜在混杂效应。手术后4周处死大鼠，取出比目鱼肌进行分析。雌激素替代减少体重，相对体重增加，比目鱼肌纤维大小，尽管所有组有类似的食物摄入量。单独卵巢切除术对这些参数没有影响，表明雌激素可能抑制骨骼肌生长时，它是唯一的卵巢激素。卵巢切除术和雌激素替代治疗均不影响最大比等长收缩力。雌激素替代增加了半弛豫时间。卵巢切除术导致达到峰值紧张的时间减少，而雌激素替代治疗则逆转了这一点。这种减少并不伴随着肌球蛋白重链组成的变化，这意味着钙处理可能已经改变。这项研究的结果表明，雌激素影响骨骼肌的生长和抽搐动力学。
This study examined the effect of estrogen replacement on soleus muscle size and contractile function in ovariectomized rats during physiological growth. Seven week old female Sprague-Dawley rats were assigned to one of three treatment groups: (1) control animals (SHAM), (2) ovariectomized animals without estrogen replacement (OVX/CO), and (3) ovariectomized animals with 17beta-estradiol replacement (OVX/E2). OVX/CO and OVX/E2 animals were pair-fed to SHAM animals to rule out the potentially confounding effect of differences in food intake. Rats were sacrificed 4 weeks after surgery and the soleus muscle was removed for analysis. Estrogen replacement reduced body weight, relative body weight gain, and soleus muscle fiber size despite all groups having a similar food intake. Ovariectomy alone had no effect on any of these parameters suggesting that estrogen may inhibit skeletal muscle growth when it is the only ovarian hormone present. Neither ovariectomy nor estrogen replacement affected maximal specific isometric force. Estrogen replacement increased half relaxation time. Ovariectomy resulted in a reduction in time to peak tension that was reversed with estrogen replacement. This reduction was not accompanied by a change in myosin heavy chain composition implying that calcium handling may have been altered. Results from this study suggest that estrogen affects skeletal muscle growth and twitch kinetics.