被动吸烟大鼠骨量与骨生物力学指标的相关性及淫羊藿黄酮的干预效应

Correlation of bone mass to bone biomechanical indexes and pharmacological effect of epimedium pubescens flavonoid in the passive smoking rats

目的：作者已通过实验证实，被动吸烟可以增加大鼠骨吸收，最终导致骨质疏松。淫羊藿黄酮有促进骨形成防止骨丢失的作用。观察淫羊藿黄酮干预对被动吸烟大鼠骨密度与骨生物力学指标的影响，并分析骨密度与骨生物力学指标的相关性。方法：实验于2005-01/12在中南大学湘雅医学院附属湘雅医院动物实验室和中心实验室完成，对动物的处置方法符合动物伦理学要求。选择SD大鼠60只，按随机数字表法分成6组（n=10）：即空白对照组、被动吸烟组、被动吸烟＋钙组、淫羊藿黄酮75，150，300mg/（k·d）组，后5组大鼠按密室熏烟法被动吸烟4个月，每天灌服钙剂及淫羊藿，给药4个月。干预完毕后测定股骨和腰椎骨密度、L4椎体力学性能指标、股骨结构力学性能指标及材料力学性能指标，并分析骨密度与骨生物力学指标的相关性。结果：60只大鼠全部进入结果分析。①与空白对照组比较，被动吸烟组大鼠的股骨和腰椎骨密度、L4椎体力学性能指标、股骨结构力学性能指标及材料力学性能指标均明显降低（P〈0．05）；与被动吸烟组比较，被动吸烟＋钙组、淫羊藿黄酮各剂量组上述指标均得到改善（P〈0．05）。②股骨和腰椎骨密度分别与腰椎体力学性能指标中弹性模量、最大载荷、最大应力、变形位能、结构刚度，股骨结构力学性能指标中最大载荷、破坏载荷、变形位能、结构刚度和股骨材料力学性能指标中弹性模量、最大应力、最大应变、破坏应力呈正相关（股骨骨密度：r=0．802～0．822，P〈0．05；腰椎骨密度：r=0．784～0．843，P〈0．05）。结论：淫羊藿黄酮可改善和提高被动吸烟大鼠骨密度、椎骨力学性能、股骨结构力学性能和材料力学性能，且骨密度与骨生物力学指标方闻存存明湿的相关性。

AIM： Authors have confirmed that passive smoking can increase rat bone resorption, resulting in osteoporosis by study. Epimedium pubescens flavonoid （EPF） can promote bone formation and prevent bone loss. This study explored the effect of EPF on the bone mineral density （BMD） and bone biomechanical properties in the experimental rats, and analyzed the correlations between BMD and the bone biomechanical properties. METHODS： Experiments were performed at the Animal Laboratory and Central Laboratory of Xiangya Hospital of Xiangya Medical College of Central South University from January to December 2005. The protocol was in accordance with animal ethical standards. Sixty Sprague-Dawley （SD） rats were randomly divided into six groups （n=10）, a blank control group, a passive smoking group （sham group）, a passive smoking plus calcium group （sham＋Ca group）, EPF 75, 150, 300 mg/（kg · d） groups. Rats in the passive smoking group, passive smoking plus calcium group, EPF 75, 150, 300 mg/（kg · d） groups received passive smoking in a cloud chamber for four months, and were daily treated with calcium agent or EPF for four months. BMD of the femur and lumbar vertebra, biomechanical properties of the fourth lumbar vertebra body （L4）, structural dynamics properties and material mechanics properties of the compact femur were measured after administration. Correlation between the BMD and the bone biomechanical properties was analyzed. RESULTS： A total of 60 rats were included in the final analysis. Compared to the blank control group, BMD of the femur and lumbar vertebra, biomechanical properties of the fourth lumbar vertebra body （L4）, structural dynamics properties and material mechanics properties of the compact femur were decreased in the passive smoking group （P 〈 0.05）, Compared to the passive smoking group, above-mentioned indexes were improved in the passive smoking plus calcium group and EPF 75, 150, 300 mg/（kg ·d） groups （P 〈 0.05）. BMD of the femur and lumbar vertebra was positively correlated with elastic modulus, maximus load, maximus stress, potential energy of deformation, structural rigidity of the biomechanical properties of the fourth lumbar vertebra body （L4）, maximus load, failure load, potential energy of deformation, structural rigidity of the structural dynamics properties of the compact femur, elastic modulus, maximus stress, maximus strain, failure stress of the material mechanics properties of the compact femur （BMD of the femur： r=-0.802-0.822, P 〈 0.05; BMD of the lumbar vertebra： r =0.784-0.843, P 〈 0.05）. CONCLUSION： EPF can improve and elevate BMD, the biomechanical properties of the fourth lumbar vertebra body （L4）, the structural dynamics properties and the material mechanics properties of the compact femur in passive smoking rats. BMD and the bone biomechanical indexes have significant correlations.