BONE MAGNESIUM POOLS IN UREMIA
BONE MAGNESIUM POOLS IN UREMIA
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DOI：
10.1172/jci107500
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发表时间：
1973-01-01
影响因子：
15.9
通讯作者：
MILLER, NL
中科院分区：
文献类型：
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作者：
ALFREY, AC;MILLER, NL
体外研究了对照组、慢性肾功能衰竭患者肾移植前后和慢性低镁血症患者的骨标本中的骨镁池。30%的骨镁存在于水化壳内或晶体表面的表面有限的水池中。较大比例的骨镁被证明与骨基质无关，而是骨晶体的组成部分。焚烧时，这个骨水池是在骨晶体大小突然增大的同一温度下被动员起来的。这表明，加热导致表面钙从磷灰石晶体中置换镁。在慢性肾功能衰竭患者中，两种镁库均增加。决定骨骼中镁浓度的主要因素似乎是血清镁水平。肾移植后，随着血清镁的下降，表面镁在正常范围内，而残余镁与其他尿骨没有区别。慢性低镁血症患者的两个镁库均显著减少。体外研究表明，表面镁应该能迅速反映血清镁水平的变化，而更深的镁池可能是在骨形成时沉积的，动员取决于吸收过程。由于镁可以影响晶体的大小和稳定性，因此过量的骨镁似乎可能在肾性骨营养不良中起作用。
Bone magnesium pools were studied in vitro in bone specimens obtained from control subjects, from patients with chronic renal failure before and after renal transplantation, and in a patient with chronic hypomagnesemia. 30% of bone magnesium is in a surface limited pool present either within the hydration shell or else on the crystal surface. The larger fraction of bone magnesium was shown not to be associated with bone matrix but rather to be an integral part of the bone crystal. With incineration this pool was mobilized at the same temperature that sudden enlargement of bone crystal size occurred. It is suggested that heating causes surface calcium to displace magnesium from the apatite crystal. Both magnesium pools are increased in patients with chronic renal failure.The major factor determining magnesium concentration in bone would appear to be the serum magnesium level. Following renal transplantation, in association with the fall in serum magnesium, surface magnesium was within the normal range; whereas, residual magnesium was not different from the other urenic bones. Both magnesium pools were significantly reduced in a patient with chronic hypomagnesemia. The in vitro studies would suggest that surface magnesium should rapidly reflect changes in serum magnesium levels, whereas, the deeper magnesium pool is probably deposited at time of bone formation with mobilization being dependent upon the resorptive processes. Since magnesium can influence crystal size and stability it seems possible that excess bone magnesium may play a role in renal osteodystrophy.