GENERATION OF OXYGEN RADICALS AND MECHANISMS OF INJURY PREVENTION
GENERATION OF OXYGEN RADICALS AND MECHANISMS OF INJURY PREVENTION
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DOI：
10.2307/3432217
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发表时间：
1994-12-01
影响因子：
10.4
通讯作者：
CASTRANOVA, V
中科院分区：
文献类型：
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作者：
CASTRANOVA, V
暴露于结晶二氧化硅可能会导致肺实质损伤和疤痕，从而导致纤维化。肺损伤可能是石英颗粒和细胞膜之间的毒性相互作用的直接结果，也可能是由于二氧化硅诱导的肺吞噬细胞产生氧化剂物质，进而破坏肺抗氧化系统并导致肺损伤。数据表明，研磨或破碎石英颗粒会破坏Si-O键并产生Si-。和Si-O-。解理面表面上的自由基。与水接触后，这些二氧化硅基自由基会产生羟基自由基（（OH）-O-.）。这些表面自由基随着破碎的二氧化硅粉尘的老化而衰减。新鲜破碎的石英在直接引起脂质过氧化、膜损伤和细胞死亡方面明显比老化的二氧化硅更有效。此外，新鲜研磨的二氧化硅是比老化二氧化硅更有效的肺泡巨噬细胞刺激剂。这种二氧化硅诱导的活化导致超氧化物（O-2（-））、过氧化氢（H2 O2）、一氧化氮（NO.）以及其他可能损害肺细胞的氧化剂种类。汉防己甲素是一种在矽肺大鼠模型中表现出抗纤维化活性的草药，可有效阻断石英刺激肺吞噬细胞释放氧化剂的能力。
Exposure to crystalline silica can result in damage to the lung parenchyma and scarring that can lead to fibrosis. Pulmonary damage may be the direct consequence of toxic interaction between quartz particles and cell membranes, or it may be due to silica-induced production of oxidant species by pulmonary phagocytes, that in turn overwhelms pulmonary antioxidant systems and causes lung injury. Data indicate that grinding or fracturing quartz particles breaks Si-O bonds and generates Si-. and Si-O-. radicals on the surface of the cleavage planes. Upon contact with water, these silica-based radicals can generate hydroxyl radicals ((OH)-O-.). These surface radicals decay as fractured silica dust is aged. Freshly fractured quartz is significantly more potent than aged silica in directly causing lipid peroxidation, membrane damage, and cell death. Furthermore, freshly ground silica is a more potent stimulant of alveolar macrophages than aged silica. This silica-induced activation results in the production of superoxide (O-2(-)), hydrogen peroxide (H2O2), nitric oxide (NO.), and other oxidant species that can damage lung cells. Tetrandrine, an herbal medicine that exhibits antifibrotic activity in rat models of silicosis, effectively blocks the ability of quartz to stimulate oxidant release from pulmonary phagocytes.