Lemke M, Yum S W, Faden A I
Department of Neurology, University of California, San Francisco.
Mol Chem Neuropathol. 1990 Jun;12(3):147-65. doi: 10.1007/BF03159941.
Secondary neurochemical events contribute to progressive tissue damage and subsequent neurological deficit after traumatic spinal-cord injury (SCI). Among proposed injury factors are alterations of phospholipids and certain cations. To clarify the relationship of membrane lipid changes (phospholipids, cholesterol, and arachidonic acid) to changes in tissue content of water and selected ions (sodium, potassium, and magnesium) after SCI, these variables were examined in spinal-cord segments from anesthetized ventilated rabbits subjected to laminectomy or to moderate (40 g-cm) or severe (150 g-cm) impact trauma at the lumbar (L2) segment. Trauma caused significant increases in tissue sodium, water, and arachidonic acid content, and significant decreases in phospholipids, cholesterol, potassium, and magnesium content. Alterations in magnesium were significantly related to injury severity. In contrast, changes in spinal-cord water content occurred to a similar degree in the two injury groups, as did tissue sodium and potassium content. Decreases in phospholipids were strongly correlated with decreases in tissue magnesium content, whereas changes in sodium and potassium were less well-correlated. Because magnesium ions play a critical role with regard to cellular bioenergetic state, calcium flux, amino acid receptor function, and eicosanoid production, reductions in tissue magnesium after injury may be important in the progression of secondary tissue damage.
继发性神经化学事件会导致创伤性脊髓损伤（SCI）后组织的渐进性损伤及随后的神经功能缺损。在已提出的损伤因素中包括磷脂和某些阳离子的改变。为了阐明脊髓损伤后膜脂质变化（磷脂、胆固醇和花生四烯酸）与组织水含量及所选离子（钠、钾和镁）变化之间的关系，对接受了椎板切除术或在腰段（L2）受到中度（40 g-cm）或重度（150 g-cm）撞击创伤的麻醉通气兔的脊髓节段中的这些变量进行了检测。创伤导致组织钠、水和花生四烯酸含量显著增加，而磷脂、胆固醇、钾和镁含量显著降低。镁的改变与损伤严重程度显著相关。相比之下，两个损伤组脊髓水含量的变化程度相似，组织钠和钾含量的变化也是如此。磷脂的减少与组织镁含量的减少密切相关，而钠和钾的变化相关性则较弱。由于镁离子在细胞生物能状态、钙通量、氨基酸受体功能和类花生酸生成方面起着关键作用，损伤后组织镁含量的降低可能在继发性组织损伤的进展中具有重要意义。
