水浴法低强度脉冲超声治疗对老年小鼠早期骨代谢血生化指标影响

Effect of underwater low intensity pulsed ultrasound on early biochemical markers of bone metabolism in aged mice

摘要:

目的：初步探索水浴法超声治疗装置的可行性，研究水浴法超声治疗对老年小鼠早期骨代谢血生化指标影响。方法：44只雌性C57BL6小鼠随机分为12～14个月的假照组和超声组，20～23个月的假照组与超声组。构建水浴超声治疗装置并采用低强度脉冲超声（low intensity pulsed ultrasound，LIPUS）水浴法进行辐照。采用COMSOL 5.3软件包对水浴超声治疗装置进行理论仿真模拟，绘制声压分布图。小鼠经眼眶取血，使用全自动生化仪检测血钙离子（calcium，Ca）与血磷离子（phosphorus，P）水平。采用酶联免疫吸附测定法检测骨特异性碱性磷酸酶（bone alkaline phosphatase，BALP）与Ⅰ型胶原羧基端肽β特殊序列（β isomer of C-terminal telopeptide of type Ⅰ collagen，β-CTX）。结果：水浴法LIPUS能成功穿透骨皮质，在骨髓腔仍有声压分布。20～23个月的小鼠与12～14个月小鼠对比，血Ca、P与β-CTX（P=0.611，P=0.660，P=0.855）无统计学差异，但其BALP水平明显降低[（2.24±0.70） vs. （4.35±1.87），P=0.002]。12～14个月与20～23个月的超声组的小鼠与假照组相比血Ca水平明显下降[（8.42±0.29） vs. （9.59±0.30）；（8.86±0.64） vs. （9.82±0.32），P=0.000]，血P水平明显上升[（10.33±1.09） vs. （8.99±0.76）；（10.17±1.17） vs. （8.49±0.72），P=0.014；P=0.002]。BALP的表达水平明显提高[（6.17±1.09） vs. （4.35±1.84）；（5.05±0.94） vs. （2.24±0.70），P=0.006；P=0.000]，β-CTX的表达只在高龄组明显下降[（114.8±19.72） vs. （189.1±57.94），P=0.047]。结论：水浴法超声治疗装置的构建是可行的，并有效改善老年C57BL6小鼠的早期的骨代谢生化指标。

Abstract:

Objective：To preliminarily explore the feasibility of underwater low intensity pulsed ultrasound（LIPUS） device，and to study its effect on early biochemical markers of bone metabolism in aged mice. Methods：A total of 44 female C57BL6 mice were randomly divided into sham control group and ultrasound group（both groups were divided into 12-14 month subgroup and 20-23 month subgroup）. An underwater LIPUS device was constructed and used for irradiation in the corresponding groups. A theoretical simulation of the underwater LIPUS device was carried out using COMSOL 5.3 software，and a sound pressure distribution map was drawn. Orbital blood samples were collected from the mice and tested for serum levels of calcium（Ca） and phosphorus（P） using an automatic biochemical analyzer；the levels of bone alkaline phosphatase（BALP） and β isomer of C-terminal telopeptide of type I col－lagen（β-CTX） were determined by enzyme-linked immunosorbent assay. Results：The underwater LIPUS was able to penetrate the cortical bone with sound pressure distributed into the medullary cavity. Compared with the mice aged 12 to 14 months，the mice aged 20 to 23 months had no significantly different serum levels of Ca，P，and β-CTX（P=0.611，0.660，and 0.855，respectively），but had a significantly reduced BALP level（4.35±1.87 vs. 2.24±0.70，P=0.002）. Compared with the sham control group，the ultrasound group had a significantly reduced serum Ca level（12-14 month subgroup：9.59±0.30 vs. 8.42±0.29，P=0.000；20-23 month subgroup：9.82±0.32 vs. 8.86±0.64；P=0.000），a significantly increased serum P level（12-14 month subgroup：8.99±0.76 vs. 10.33±1.09，P=0.014；20-23 month subgroup：8.49±0.72 vs 10.17±1.17，P=0.002），a significantly increased expression level of BALP（12-14 month subgroup：4.35±1.84 vs. 6.17±1.09，P=0.006；20-23 month group：2.24±0.70 vs. 5.05±0.94，P=0.000），and a significantly decreased expression level of β-CTX（only in the 20-23 month subgroup：189.1±57.94 vs. 114.8±19.72，P=0.047）. Conclusion：It is feasible to construct an underwater LUPUS device，and it can effectively improve the early biochemical markers of bone metabolism in aged C57BL6 mice.