大豆异黄酮对肾辐射损伤大鼠骨量和骨结构的影响

Effects of soy isoflavones on bone mass and bone structure in rats by radioactive injury to kidney

目的观察大豆异黄酮对肾辐射损伤大鼠骨量、骨生物力学和骨形态计量的影响。方法应用15Gy137Csγ射线局部照射大鼠双侧肾脏,建立肾损伤引起继发性骨质疏松模型,以假照射组大鼠为对照。术后7d开始用药,给予大豆异黄酮(100mgkg·d),以萌格旺(0.1μgkg·d)为阳性对照药物,治疗3个月后处死大鼠,观察骨量、骨生物力学和骨形态计量学指标改变,综合评价大豆异黄酮对肾辐射损伤性骨质疏松的防治作用。结果肾辐射损伤大鼠骨量、骨生物力学指标较假照射组显著降低(P<0.05),表明肾辐射损伤引起大鼠继发性骨质疏松模型成功;大豆异黄酮治疗能明显增加模型大鼠的腰椎BMD、股骨干重与灰重,提高股骨三点弯曲最大载荷,增加腰椎骨小梁面积百分比(P<0.05)。结论大豆异黄酮对肾局部辐射损伤诱导骨质疏松模型大鼠的骨量和骨结构有明显改善作用。

Objective To study the effects of soy isoflavones on bone mineral density, histomorphometry and biomeehanics in rats with osteoporosis induced by irradiation of the rat kidney. Methods Thirty two 3-month-old male SD rats were randomly assigned into 4 groups evenly, i. e. the radiation group（Rad）, the non-radlation group （Non-Rad）, the Bon-One group（Bon-One） and the soy isoflavones group （ SI）, All rats were administrated single 15Gy ^137 Cs γ-ray irradiation by exposing double kedneys through operation except those in the Non-Rad group. From 7 days after operation,the SI group were fed by soy isoflavones 100 mg/（kg·d） ,the Bon-One group by BonOne 0.1μg/（kg·d）,the Rad group and Non-Rad group by same volume of distilled water. 90 days later, all rats were sacrificed and the following indices were observed： BMD of L1-L5, the bone histomorphometry and bone biomechanical properties. Results BMD of L1-L5, maximal load of femur and volume and number of bone trabecula decreased significantly in Rad group compared to those in Non-Rad group, which shows the model is successful, Compared with the Rad group, the SI group was characterized with significantly higher BMD of LI-L5 and maximal load of femur（ P 〈 0.05）, significantly larger volume and number of bone trabecula and smaller space of bone trabecula（ P 〈 0,05）. Conclusions Soy isoflavones can improve BMD, bone histomorphometry and bone biomechanical properties in rat osteoporosis induced by kidney irradiation.