Abstract

We explored age- and strain-related differences in bone microstructure and body composition in male C57BL/6J, DBA/2JRj and C3H/J mice. Bone microstructure of the femur, tibia and L4 was assessed by μCT at the age of 8, 16 and 24 weeks. The weight of several muscles and fat depots were measured at the same time points. At all timepoints, C3H/J mice had the thickest cortices followed by DBA/2JRj and C57BL/6J mice. Nevertheless, C57BL/6J mice had higher Tb.BV/TV and Tb.N, and lower Tb.Sp than DBA/2JRj and C3H/J mice at least at 24 weeks of age. Skeletal development patterns differed among strains. C57BL/6J and DBA/2JRj mice, but not C3H/J mice, experienced significant increases in the sum of the masses of 6 individual muscles by 24 weeks of age. In C57BL/6J and DBA/2JRj mice, the mass of selected fat depots reached highest values at 24 weeks, whist, in C3H/J mice, the highest values of fat depots masses were achieved at 16 weeks. Early strain differences in muscle and fat masses were largely diminished by 24 weeks of age. C3H/J and C57BL/6J mice displayed the most favorable cortical and trabecular bone parameters, respectively. Strain differences in body composition were less overt than strain specificity in bone microstructure, however, they possibly influenced aspects of skeletal development.

中文翻译：

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自交系雄性小鼠发育过程中骨微结构和身体组成的年龄和应变相关差异。

摘要

我们探讨了雄性C57BL / 6J，DBA / 2JRj和C3H / J小鼠的骨组织与年龄和应变相关的差异。在8、16和24周龄时通过μCT评估股骨，胫骨和L4的骨微结构。在同一时间点测量几个肌肉和脂肪仓库的重量。在所有时间点上，C3H / J小鼠的皮质最厚，其次是DBA / 2JRj和C57BL / 6J小鼠。尽管如此，至少在24周龄时，C57BL / 6J小鼠的Tb.BV/TV和Tb.N较高，而Tb.Sp却比DBA / 2JRj和C3H / J小鼠低。品系之间的骨骼发育模式不同。到24周龄时，C57BL / 6J和DBA / 2JRj小鼠（但不是C3H / J小鼠）的6条单独肌肉的质量总和显着增加。在C57BL / 6J和DBA / 2JRj小鼠中，选定的脂肪仓库的质量在24周时达到最高值，在C3H / J小鼠中，在16周时达到最高的脂肪仓库质量值。到24周龄时，早期肌肉和脂肪量的应变差异已大大降低。C3H / J和C57BL / 6J小鼠分别显示出最有利的皮质和小梁骨参数。身体组成中的应变差异没有骨微观结构中的应变特异性明显，但是，它们可能影响骨骼发育的各个方面。