Growth rate rather than gender determines the size of the adaptive response of the growing skeleton to mechanical strain
Growth rate rather than gender determines the size of the adaptive response of the growing skeleton to mechanical strain
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DOI：
10.1016/s8756-3282(01)00626-3
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发表时间：
2002-01-01
期刊：
影响因子：
4.1
通讯作者：
Lanyon, LE
中科院分区：
文献类型：
--
作者：
Mosley, JR;Lanyon, LE
为了确定雄性和雌性骨骼是否对机械负荷具有相同的反应，在一组幼年雄性（n = 7）和年龄匹配的雌性（n = 9）大鼠中，除正常运动外，左尺骨还接受了短期的每日体内受控动态负荷（每天以2 Hz进行1200次循环，持续10天）。调整每组的轴向载荷，以在尺骨中段的内侧面产生-4000微应变的峰值动态应变，以+/-30，000微应变/秒的速率施加和释放。在负荷期开始和结束时给予荧光标记。在每日负荷过程中，雄性大鼠的体重增加速度是雌性大鼠的2.5倍（6.3 g/天vs. 2.5 g/天）。由于生长和正常运动，雄性的骨膜间骨面积增加也是雌性的2.5倍。与对照组相比，两种性别的受载者尺骨骨膜新骨沉积均显示出统计学显著性（p < 0.05）增加。雄性和雌性动物的成骨反应模式相似，特征是尺骨外侧面的矿物质沉积率增加，以及建模漂移相关吸收停滞，并逆转为内侧表面的骨形成。在男性中，骨面积的绝对负荷相关增加是女性的6倍。然而，当相对于生长表示骨膜标记间新骨沉积的负载相关变化的绝对大小时，雄性和雌性之间没有差异（平均值+/- SEM：雄性为37 +/- 12%，雌性为34 +/-12%）。这些数据证实，两种性别的年轻活跃生长大鼠的尺骨响应于短的每日负荷期，具有改变的建模响应，包括骨形成增加和吸收减少。尽管男性受负荷刺激的新骨形成的绝对量大于女性，但在对男性中观察到的骨沉积率较高进行校正后，性别之间没有差异，因为男性的生长速度更快。(C)2002年，Elsevier Science Inc. All rights reserved.
To determine whether male and female skeletons are equally responsive to mechanical load, the left ulnae in a group of juvenile male (n = 7), and age-matched female (n = 9) rats received a short daily period of controlled dynamic loading in vivo (1200 cycles at 2 Hz each day for 10 days) in addition to their normal exercise. Axial loads for each group were adjusted to engender a peak dynamic strain of -4000 microstrain at the medial face of the ulna midshaft, applied and released at a rate of +/-30,000 microstrain/sec. Fluorescent labels were administered at the start and finish of the loading period. Over the course of daily loading, the body mass of the male rats increased 2.5 times faster than that of the females (6.3 g/day vs. 2.5 g/day). The increase in periosteal interlabel bone area due to growth and normal exercise was also 2.5 times greater in the males than in the females. Both genders showed statistically significant (p < 0.05) increases in periosteal new bone deposition in the ulna of their loaded compared with their control limb. The pattern of osteogenic response was similar in males and females and featured increased mineral apposition rate on the lateral surface of the ulna, and arrest of modelin g-drift-related resorption with its reversal to bone formation on the medial surface. In males, the absolute loading-related increase in bone area was six times greater than that in females. How-ever, when the absolute size of the loading-related change in periosteal interlabel new bone deposition was expressed relative to that due to growth, there was no difference between males and females (Mean +/- SEM: 37 +/- 12% for males, 34 +/- 12 % for females). These data confirm that the ulna of young actively growing rats of both genders responds to a short daily period of loading with an altered modeling response that involves increased bone formation and decreased resorption. Although the absolute amount of new bone formation stimulated by loading is greater in males than in females there is no difference between genders following correction for the higher rate of bone deposition seen in the males in association,with their faster rate of growth. (C) 2002 by Elsevier Science Inc. All rights reserved.