Peng Z Q, Väänänen H K, Tuukkanen J
Department of Anatomy and Biocenter Oulu, University of Oulu, Kajaanintie 52A, SF-90220, Oulu, Finland.
Calcif Tissue Int. 1997 May;60(5):441-8. doi: 10.1007/s002239900260.
Fifty-six Sprague-Dawley rats were either ovariectomized (OVX, n = 24), sham-operated (Sham, n = 24), or sacrificed (n = 8) at the beginning of the experiment to serve as a baseline group. The OVX and Sham groups were further randomly divided into control (CTRL), slow running (R10), and faster running (R18) groups. R10 and R18 groups ran for 2 x 30 min/day for 8 weeks at speeds of 10 m/min and 18 m/min, respectively. Exercise did not affect the mechanical or histomorphometric parameters of bone in the sham-operated rats. There was no effect of exercise on body weight gain in the OVX-R10 group, but in OVX-R18 it decreased the gain of body weight. In the OVX-CTRL group the maximal load and energy absorption of the femoral neck were 16.7% (P < 0.001) and 30.0% (P < 0.001) lower than in the Sham-CTRL group, respectively. In OVX animals, slow running had a positive effect on the maximal load of the femoral neck (86.5 N) when compared with OVX-CTRL rats (77.1 N, P < 0.07). 51.7% of the trabecular bone was lost in the distal femur as a result of OVX and exercise reduced this loss to 30.2% (R10) and 39.9% (R18). Ovariectomy increased the bone formation rate (BFR) and the mineral apposition rate (MAR) on the periosteum of the femoral shaft. Exercise decreased the periosteal BFR and MAR in OVX rats, but increased it at the endosteum. Osteoclast numbers in the femoral metaphysis were increased after OVX and running exercise inhibited this effect significantly. The maximal bending load of the humerus increased after OVX by 12.1% (P < 0.05). Exercise enhanced this effect, the slow running being more effective. These results suggest that bone in OVX rats is either more sensitive to exercise than in sham-operated rats or that the higher body weight with slow running induces optimal loading and strengthens the bones.
56只Sprague-Dawley大鼠在实验开始时，一部分接受卵巢切除术（OVX，n = 24），一部分接受假手术（Sham，n = 24），还有一部分（n = 8）被处死作为基线组。OVX组和Sham组再进一步随机分为对照组（CTRL）、慢速跑步组（R10）和快速跑步组（R18）。R10组和R18组分别以10米/分钟和18米/分钟的速度每天跑步2×30分钟，持续8周。运动对假手术大鼠的骨力学和组织形态计量学参数没有影响。运动对OVX-R10组的体重增加没有影响，但在OVX-R18组中降低了体重增加。在OVX-CTRL组中，股骨颈的最大负荷和能量吸收分别比Sham-CTRL组低16.7%（P < 0.001）和30.0%（P < 0.001）。在OVX动物中，与OVX-CTRL大鼠（77.1 N，P < 0.07）相比，慢速跑步对股骨颈的最大负荷（86.5 N）有积极影响。由于OVX，51.7%的股骨远端小梁骨丢失，运动将这种丢失减少到30.2%（R10）和39.9%（R18）。卵巢切除术增加了股骨干骨膜的骨形成率（BFR）和矿物质沉积率（MAR）。运动降低了OVX大鼠的骨膜BFR和MAR，但增加了骨髓腔内的BFR和MAR。OVX后股骨近端干骺端的破骨细胞数量增加，跑步运动显著抑制了这种作用。OVX后肱骨的最大弯曲负荷增加了12.1%（P < 0.05）。运动增强了这种作用，慢速跑步更有效。这些结果表明，OVX大鼠的骨骼对运动比假手术大鼠更敏感，或者慢速跑步时较高的体重诱导了最佳负荷并增强了骨骼。
