不同性别的大鼠骨质疏松形态计量学和生物力学研究

The histomorphometry and biomechanics study of osteoporotic rats of different sex

目的研究不同性别骨质疏松大鼠的骨力学特性。方法基于切除卵巢雌性大鼠和切除肾上腺雄性大鼠骨质疏松模型,研究不同性别大鼠骨形态计量学和生物力学的测量结果。结果骨形态计量学提示,骨小梁厚度(Tb.Th)、平均骨小梁接点数(Tb.N)、相对类骨质体积(OV/BV)雌性大鼠低于雄性;四环素单标记面(sLS/BS)雌性大鼠高于雄性大鼠。生物力学指标提示,骨质疏松大鼠弯曲弹性模量、弯曲刚性系数低于正常;最大弯曲应力低于正常,且雌性低于雄性大鼠。弯曲韧性系数雄性大鼠高于正常,雌性大鼠低于正常。结论骨质疏松雌性大鼠骨小梁形态结构弱于雄性。骨质疏松大鼠抗应力强度减弱,骨韧性度雌性大鼠弱于雄性。因此,雌性大鼠骨质疏松的骨质力学状态弱于雄性。

Objective To study the bone biomechanical characteristics of osteoporotic rats with different sex. Methods Based on the osteoporotie models of ovariectomy for female rats and adrenalectomy for male rats, the bone histomorphometry and biomechanics of rats of different sex were analyzed. Results The bone histomorphometry data showed that the thickness of bone trabeeula （ Tb. Th） , number of average bone trabecula junction （ Tb. N） , and relative volume of osteoid （0V/BV） in female rats were lower than those in male ones. The index of sLS/BS in female rats was higher than that in male ones. The biomechanical results illustrated that the indexes of modulus of bending elasticity and modulus of bending rigidity in the rats with osteoporosis were both lower than those in normal rats. The index of maximal bending stress in rats with osteoporosis was lower than that in the normal rats and this index in female rats were lower than that in male rats. Conclusion The trabecular bone structure in female osteoporotie rats was weaker than that in male rats. The anti-stress intensity in osteoporotic rats weakened compared to that in normal rats. The bone ductility in female rats was weaker than that in male rats. Thus, the bone biomeehanical status in female osteoporotic rats was weaker than that in male rats.