应力环境与重组人生长激素对骨质疏松下颌骨最大载荷的影响

目的观察不同应力环境对骨质疏松下颌骨最大载荷的影响及补充生长激素对其变化的影响。方法通过去除SD大鼠双侧卵巢,拔除单侧上颌磨牙,建立骨质疏松下颌骨高、低应力环境的动物模型,用三点弯曲法检测下颌骨最大载荷的变化。结果去势后大鼠下颌骨最大载荷显著降低(P<0.01)。生长激素组双侧下颌骨最大载荷均显著高于骨质疏松组(P<0.01)。骨质疏松组下颌骨最大载荷低应力侧显著低于高应力侧(P<0.01),假手术组及生长激素组拔牙4周后双侧无明显差异,仅拔牙8周后差异有统计学意义(P<0.05)。结论低应力环境加速骨吸收,促进下颌骨骨强度的下降。补充生长激素则可阻止低应力环境下骨质疏松大鼠颌骨骨强度的下降,抑制骨吸收。

The effects of recombine human growth hormone on mandibles' maximum load in ovariectomized rats with changes of stress

Objective To study effects of the change of stress environment and recombine human growth hormone therapy on mandibles' maximum load in ovariectomized rats. Methods Animal models were established by ovariectomy and exodontias on left partial maxillary. And the effects of different stress environment and recombine human growth hormone on mandible's maximum load were observed by three-point bend test. Results Mandibles' maximum load in ovariectomized rats significantly decreased(P<0.01), and mandibles' maximum load in human growth hormone recombinant group(rh-GH) was obviously higher than that in postmenopausal osteoporosis group (PMO) (P<0.01). Maximum load of the low stress mandibles was significantly lower than that of the high stress mandibles in PMO group (P<0.01). Maximum load of the low stress mandibles was lower than that of the high stress mandibles in rh-GH group and sham-ovariectomized group (sham-OVX), but the difference had statistical significance only 8 weeks after extraction (P<0.01). Conclusion Low stress environment may promote loss of bone mass and degradation of bone strength. Bone loss and decrease of bone strength can be hindered by treatment with human growth hormone.