Bioengineering Division, Osaka University Graduate School of Engineering Science, 1-3 Machikaneyama-cho, Toyonaka, 560-8531, Japan.
Biol Trace Elem Res. 2012 Dec;150(1-3):278-84. doi: 10.1007/s12011-012-9466-x. Epub 2012 Jun 16.
In chronic kidney disease (CKD), osteodystrophy and arterial calcification often coexist. However, arterial alterations have not been addressed in CKD unaccompanied by evidence of calcification. We investigated the association of phosphate (P) and calcium (Ca) accumulation in calcification-free aortas with CKD-induced osteodystrophy. Aortic accumulation of magnesium (Mg), an inhibitor of calcification, was also examined. Male mice aged 26 weeks with CKD characterized by hyperparathyroidism and hyperphosphatemia (Nx, n = 8) and age-matched healthy male mice (shams, n = 8) were sampled for blood, and thoracic vertebrae and aortas were harvested. Bone structure and chemicals were analyzed by microcomputed tomography and infrared microspectroscopy, respectively, and aortic accumulation of P, Ca, and Mg was evaluated by plasma-atomic emission spectrometry. Volume fractions of cortical and trabecular bones were smaller in Nx than in sham animals (P < 0.05), attributed to cortical thinning and reduction in trabecular number, respectively. Bone chemicals were not different between the groups. No calcification was found in either group, but P, Ca, and Mg contents were higher in Nx than in shams (P < 0.05). The mass ratio of Ca/P was lower in Nx than in shams (P < 0.05), but that of Mg/Ca and Mg/P was not different between the groups. Aortic P and Ca contents were inversely correlated with the volume fraction of cortical bone (P < 0.05). In conclusion, the relationship of osteodystrophy with aortic P and Ca accumulation suggests the existence of a bone-vascular axis, even in calcification-free arteries in CKD. The preservation of ratios of Mg/Ca and Mg/P despite CKD development might contribute to calcification resistance.
在慢性肾脏病（CKD）中，骨营养不良和动脉钙化通常并存。然而，在没有钙化证据的 CKD 中，动脉改变尚未得到解决。我们研究了无钙化的 CKD 中主动脉内磷酸盐（P）和钙（Ca）积累与 CKD 诱导的骨营养不良之间的关系。还检查了钙化抑制剂镁（Mg）在主动脉中的积累。采集了 26 周龄具有甲状旁腺功能亢进和高磷血症的 CKD 特征的雄性小鼠（Nx，n=8）和年龄匹配的健康雄性小鼠（shams，n=8）的血液、胸椎体和主动脉。通过微计算机断层扫描和红外微光谱分别分析骨结构和化学成分，并通过等离子体原子发射光谱评估主动脉内 P、Ca 和 Mg 的积累。与 sham 动物相比，Nx 中的皮质骨和小梁骨体积分数较小（P<0.05），这归因于皮质变薄和小梁数量减少。两组之间的骨化学物质没有差异。两组均未发现钙化，但 Nx 中的 P、Ca 和 Mg 含量高于 sham 组（P<0.05）。Nx 中的 Ca/P 质量比低于 sham 组（P<0.05），但 Mg/Ca 和 Mg/P 之间的比值在两组之间没有差异。主动脉 P 和 Ca 含量与皮质骨体积分数呈负相关（P<0.05）。总之，骨营养不良与主动脉 P 和 Ca 积累之间的关系表明，即使在 CKD 无钙化的动脉中，也存在骨血管轴。尽管 CKD 发展，但 Mg/Ca 和 Mg/P 比值的保留可能有助于抵抗钙化。
