Mak I T, Dickens B F, Komarov A M, Wagner T L, Phillips T M, Weglicki W B
Department of Medicine, George Washington University Medical Center, Washington, DC 20037, USA.
Mol Cell Biochem. 1997 Nov;176(1-2):35-9.
Sprague-Dawley rats (200 g) were fed either a Mg-deficient or Mg-sufficient diet for 3 weeks. An enriched neutrophil fraction (> 85%) was isolated from the blood by sodium metrizoate/dextran gradient centrifugation. Using the superoxide dismutase. (SOD)-inhibitable cytochrome c reduction assay, the basal activity of neutrophils isolated from the Mg-deficient rats were found elevated 5 fold after two weeks, and up to approximately 7 fold after three weeks on the diet. Upon challenge by phorbol myristate acetate (PMA), unlike the Mg-sufficient cells, the Mg-deficient cells exhibited no significant activation. Treatment of the Mg-deficient rats with the nitric oxide (NO)-synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME) in the drinking water, significantly attenuated the basal superoxide producing activity of the neutrophils and partially restored its response to PMA challenge. In association with the neutrophil activation. Mg-deficiency resulted in 70% decrease in plasma glutathione and 220% increase in Fe-promoted, thiobarbituric acid reactive substance (TBARS) levels; both changes were significantly attenuated by L-NAME treatment. The results suggest that neutrophils from Mg-deficient rats are activated endogenously to generate oxy-radicals which might directly mediate the in vivo peroxidative indices during Mg-deficiency. Furthermore, the neutrophil activity was lowered by NO-synthase inhibition suggesting that NO overproduction during Mg-deficiency participates in the neutrophil activation process.
将200克的斯普拉格-道利大鼠分为两组，分别喂食缺镁饮食或充足镁饮食，为期3周。通过甲泛影酸钠/葡聚糖梯度离心法从血液中分离出富含中性粒细胞的部分（>85%）。使用超氧化物歧化酶（SOD）抑制的细胞色素c还原试验，发现从缺镁大鼠分离出的中性粒细胞的基础活性在两周后升高了5倍，在饮食3周后高达约7倍。在用佛波醇肉豆蔻酸酯乙酸酯（PMA）刺激后，与镁充足的细胞不同，缺镁的细胞没有表现出明显的激活。给缺镁大鼠饮用含一氧化氮（NO）合酶抑制剂NG-硝基-L-精氨酸甲酯（L-NAME）的水，显著减弱了中性粒细胞的基础超氧化物产生活性，并部分恢复了其对PMA刺激的反应。与中性粒细胞激活相关，缺镁导致血浆谷胱甘肽减少70%，铁促进的硫代巴比妥酸反应性物质（TBARS）水平增加220%；L-NAME处理显著减弱了这两种变化。结果表明，缺镁大鼠的中性粒细胞被内源性激活以产生氧自由基，这可能直接介导了缺镁期间体内的过氧化指标。此外，NO合酶抑制降低了中性粒细胞活性，表明缺镁期间NO的过度产生参与了中性粒细胞激活过程。
