Effects of ovariectomy and hindlimb unloading on skeletal muscle
Effects of ovariectomy and hindlimb unloading on skeletal muscle
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DOI：
10.1152/jappl.1998.85.4.1316
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发表时间：
1998-10-01
影响因子：
3.3
通讯作者：
Brown, M
中科院分区：
文献类型：
--
作者：
Fisher, JS;Hasser, EM;Brown, M
雌性大鼠(7~8月龄，n=40)随机分为正常对照组(Int)和去卵巢对照组(OVX)。摘除卵巢2周后，动物又分为去卵巢2周后肢去荷组(Int-HU)和去卵巢后肢去荷组(OVX-HU)。我们假设，与Int大鼠相比，OVX大鼠的后肢卸载相关萎缩程度更大。对比目鱼肌(SOL)、足底肌(PLAN)、腓骨长肌(PER)和趾长伸肌(EDL)进行了原位收缩试验。OVX组大鼠体重和SOL质量比Int组大22%，HU组和Int组大鼠体重和SOL质量比Int组大约18%(OVX X Hu交互作用，P<；0.05)，Plan肌肉也有类似趋势(P<；0.07)。卵巢切除(生长)和后肢卸载(萎缩)对腓肠肌质量均有显著影响(P<；0.05)。卵巢切除或后肢卸载均不影响PER和EDL肌肉的质量。OVX组EDL的收缩张力达到峰值的时间和SOL、PLAN、PER和EDL肌的一半松弛时间比Int动物快(P<；0.05)。结果表明：1)卵巢切除导致体重和足底屈肌质量类似地增加了20%；2)后肢卸载可能阻止了卵巢切除相关肌肉的生长；3)与对照组相比，去卵巢动物的SOL和PLAN可能发生了更大的萎缩；以及4)去除卵巢激素的影响减少了骨骼肌收缩时间。
Female rats (7-8 mo old, n = 40) were randomly placed into the intact control (Int) and ovariectomized control (Ovx) groups. Two weeks after ovariectomy, animals were further divided into intact 2-wk hindlimb unloaded (Int-HU) and ovariectomized hindlimb unloaded (Ovx-HU). We hypothesized that there would be greater hindlimb unloading-related atrophy in Ovx than in Int rats. In situ contractile tests were performed on soleus (Sol), plantaris (Plan), peroneus longus (Per), and extensor digitorum longus (EDL) muscles. Body weight and Sol mass were similar to 22% larger in Ovx than in Int group and similar to 18% smaller in both HU groups than in Int rats (Ovx X HU interaction, P < 0.05), and there was a similar trend in Plan muscle (P < 0.07). There were main effects (P < 0.05) for both ovariectomy (growth) and hindlimb unloading (atrophy) on gastrocnemius mass. Mass of the Per and EDL muscles was unaffected by either ovariectomy or hindlimb unloading. Time to peak twitch tension for EDL and one-half relaxation times for Sol, Plan, Per, and EDL muscles were faster (P < 0.05) in Ovx than in Int animals. The results suggest that I) ovariectomy led to similar increases of similar to 20% in body weight and plantar flexor mass; 2) hindlimb unloading may have prevented ovariectomy-related muscle growth; 3) greater atrophy may have occurred in Sol and Plan of Ovx animals compared with controls; and 4) removal of ovarian hormonal influence decreased skeletal muscle contraction times.