口服牛骨胶原肽对模拟微重力条件下大鼠股骨微结构的改善效应

Effect of oral administration of bovine collagen peptide on femoral microstructure in rats subjected to simulated microgravity

目的观察胶原肽(collagen peptides,CP)对模拟微重力(simulated microgravity,SMG)条件下大鼠骨代谢指标及骨微结构的影响。方法雄性SD大鼠24只随机平均分为3组:水平对照组(control,CN),后肢尾吊模拟失重组(SMG组),模拟失重同时给予CP灌胃组(CP组)。CN和SMG组灌等量双蒸水,各组实验期均为28 d。采用全自动生化分析仪检测血清钙(Ca)、磷(P)及碱性磷酸酶(alkaline phosphatase,ALP)含量,放射免疫法检测血清骨钙素(osteocalcin,OC)含量;Micro-CT分析右侧股骨远端的骨微结构;Masson染色观察右侧胫骨近端骨胶原纤维。结果 SMG+CP显示骨保护作用:抑制SMG诱导的血清Ca、ALP和OC含量的降低,改善股骨远端的微结构(增加骨体积相对含量及骨小梁数量,能抑制骨小梁完整性的减少),同时抑制SMG所致的胶原纤维含量的降低。结论口服牛骨CP能明显改善SMG大鼠股骨微结构,从而为微重力条件下骨质疏松的防治提供理论依据。

Objective To study the bone turnover and femoral microstructural changes induced by oral administration of bovine collagen peptide（ CP） in rats subjected to simulated microgravity. Methods Twenty-four male Sprague-Dawley rats were divided into 3 groups： normal control（ CN） group,simulated microgravity（ SMG） group by tail suspension,SMG with once-daily intragastric administration of 750 mg / kg bovine CP group. CN and SMG groups were given the same dose of normal saline,and the experimental period was 28 d. Serum calcium,phosphorus and alkaline phosphatase（ ALP） were measured by an autoanalyzer（ Model 7060; Hitachi,Tokyo,Japan）,osteocalcin（ OC） by radioimmunometric assay and microstructure of the distal end of the right femurs was analyzed by micro CT,and the changes of collagen fibers in the proximal end of tibia were observed with Masson staining. Results SMG ＋ CP produccd osteoprotective effects,as shown by the inhibition of the SMG-induced reductions of serum calcium, ALP and OC levels and improvement of the microarchitecture of the distal femur（ the increase of bone volume and bone trabecular number,inhibition of SMG-induced trabecular alteration and collagen reduction）. Conclusion Oral administration of bovine CP may produce beneficial efficacy on SMG-induced femoral microstructure changes in rats,which provides a theoretical basis for the prevention and treatment of osteoporosis in a microgravity environment.