Vink R, Yum S W, Lemke M, Demediuk P, Faden A I
Center for Neural Injury, University of California, San Francisco.
Brain Res. 1989 Jun 19;490(1):144-7. doi: 10.1016/0006-8993(89)90440-x.
The mechanisms by which traumatic injury to the central nervous system cause irreversible tissue damage remain speculative. Recent reports suggest that a decrease in tissue total and free Mg2+ concentration may be an important factor in the development of such injury after experimental brain trauma. Although total Mg changes have been reported following spinal cord trauma, no studies have examined spinal cord-free Mg2+. In the present study, we have used phosphorus magnetic resonance spectroscopy to determine intracellular free Mg2+ concentration and atomic absorption spectrophotometry to measure total tissue Mg concentration in rabbit spinal cord prior to and following impact trauma. We report that intracellular free Mg2+ concentration decreases from a pre-injury value of 0.80 +/- 0.12 mM (mean +/- S.E.M.) to 0.31 +/- 0.05 mM at 2 h post-trauma. Following injury there was an associated decrease in total tissue Mg and K concentration, but no alterations in tissue Na or water content.
中枢神经系统创伤导致不可逆组织损伤的机制仍属推测。最近的报告表明，组织总镁离子和游离镁离子浓度的降低可能是实验性脑创伤后此类损伤发展的一个重要因素。尽管脊髓创伤后已有总镁离子变化的报道，但尚无研究检测脊髓游离镁离子。在本研究中，我们使用磷磁共振波谱法测定兔脊髓撞击伤前后细胞内游离镁离子浓度，并使用原子吸收分光光度法测量组织总镁离子浓度。我们报告，创伤后2小时，细胞内游离镁离子浓度从损伤前的0.80±0.12 mM（平均值±标准误）降至0.31±0.05 mM。损伤后，组织总镁离子和钾离子浓度随之降低，但组织钠离子或水含量无变化。
