Department of Mechanical Engineering, McMaster School of Biomedical Engineering, McMaster University, 1280 Main Street West, Office: ETB 411, Hamilton, ON, Canada.
Bone. 2013 Jan;52(1):63-9. doi: 10.1016/j.bone.2012.09.002. Epub 2012 Sep 17.
Strontium ranelate is an approved pharmacotherapy for osteoporosis in Europe and Australia, but not in Canada or the United States. Strontium citrate, an alternative strontium salt, however, is available for purchase over-the-counter as a nutritional supplement. The effects of strontium citrate on bone are largely unknown. The study's objectives were 1) to quantify bone strontium accumulation in female Sprague Dawley rats administered strontium citrate (N=7) and compare these levels to rats administered strontium ranelate (N=6) and vehicle (N=6) over 8 weeks, and 2) to verify an in vivo X-ray fluorescence spectroscopy (XRF) system for measurement of bone strontium in the rat. Daily doses of strontium citrate and strontium ranelate were determined with the intention to achieve equivalent amounts of elemental strontium. However, post-hoc analyses of each strontium compound conducted using energy dispersive spectrometry microanalysis revealed a higher elemental strontium concentration in strontium citrate than strontium ranelate. Bone strontium levels were measured at baseline and 8 weeks follow-up using a unique in vivo XRF technique previously used in humans. XRF measurements were validated against ex vivo measurements of bone strontium using inductively coupled plasma mass spectrometry. Weight gain in rats in all three groups was equivalent over the study duration. A two-way ANOVA was conducted to compare bone strontium levels amongst the three groups. Bone strontium levels in rats administered strontium citrate were significantly greater (p<0.05) than rats administered strontium ranelate and vehicle. ANCOVA analyses were performed with Sr dose as a covariate to account for differences in strontium dosing. The ANCOVA revealed differences in bone strontium levels between the strontium groups were not significant, but that bone strontium levels were still very significantly greater than vehicle.
雷奈酸锶在欧洲和澳大利亚被批准用于骨质疏松症的药物治疗，但在加拿大和美国则没有。然而，枸橼酸锶，一种替代的锶盐，可以作为营养补充剂在柜台上购买。枸橼酸锶对骨骼的影响在很大程度上是未知的。该研究的目的是 1）定量测定给予枸橼酸锶（N=7）的雌性 Sprague Dawley 大鼠的骨锶积累，并将这些水平与给予雷奈酸锶（N=6）和载体（N=6）的大鼠进行比较，共 8 周，2）验证用于测量大鼠骨锶的体内 X 射线荧光光谱（XRF）系统。枸橼酸锶和雷奈酸锶的日剂量是根据意图达到等量的元素锶来确定的。然而，使用能量色散光谱微量分析对每种锶化合物进行的事后分析表明，枸橼酸锶中的元素锶浓度高于雷奈酸锶。使用以前在人类中使用的独特的体内 XRF 技术，在基线和 8 周随访时测量骨锶水平。XRF 测量值通过电感耦合等离子体质谱法对骨锶的体外测量值进行验证。在研究期间，三组大鼠的体重增加均相当。进行了双向方差分析以比较三组之间的骨锶水平。给予枸橼酸锶的大鼠的骨锶水平明显高于给予雷奈酸锶和载体的大鼠（p<0.05）。进行了协方差分析（ANCOVA），将 Sr 剂量作为协变量，以解释锶剂量的差异。ANCOVA 表明锶组之间的骨锶水平差异不显著，但骨锶水平仍明显高于载体。
