超细碳黑对肺泡Ⅱ型上皮细胞的氧化损伤作用

Oxidative injury of alveolar epithelium cell Ⅱ affected by ultrafine carbon black

目的研究超细碳黑(Ulfrafine carbon black,UFCB)对肺泡Ⅱ型上皮细胞A549的氧化损伤作用。方法A549细胞暴露于不同浓度的UFCB颗粒物混悬液(50、200、800μg/ml),染毒24 h后采用噻唑蓝(MTT)法测细胞存活率,测定细胞培养上清液中的乳酸脱氢酶(LDH)释放水平和细胞内超氧化物歧化酶(SOD)含量,并通过鲁米诺诱导的化学发光法测定细胞内氧自由基水平。结果随着染毒浓度上升,A549细胞存活率下降,细胞培养上清液中的LDH活力(U/L)逐渐增加,分别为2947.89±157.90、3087.51±157.90和3183.58±118.85 U/L。细胞内SOD含量降低,显示出浓度依赖关系,中、高浓度组结果差异有统计学意义,分别为53.28±4.56和47.62±4.73(U/g prot)。鲁米诺诱导的化学发光平均每秒的照度,随着染毒浓度的增高而逐渐增加,并且与对照组相比差异均有统计学意义。结论UFCB对肺泡Ⅱ型上皮细胞有氧化损伤作用,对颗粒本身渗透进入间隙组织,进一步损伤肺部有一定意义。

Objective To study oxidative injury of ultrafine carbon black（UFCB）on alveolar epithelium cell Ⅱ .Methods A549 cells were exposed to ultrafine carbon black with different concentrations （50,200,800 μg/ml）.The viability of cells was checked by methyl thiazolyl tetrazolium（MTT） after 24 h exposure. Meantime, the activity of lactate dehydrogenase（LDH） in cell culture supernatant and the concentration of superoxide dismutase （SOD） in cells were determined. The level of oxygen free radical in the cells was detected by chemiluminescence induced luminol. Resldts The survival rate of A549 cells descended gradually with increase of exposure concentration and showed a exposure-response relationship. The levels of LDH in supernatant of culture medium （U/L） were significantly increased which were 2947.89 ± 157.90, 3087.51 ± 157.90 and 3183.58 ± 118.85 and SOD contents in cells were significantly decreased in exposed groups （middle and high exposed groups） compared with the controls, which were 53.28 ± 4.56 and 47.62 ± 4.73, both showing obvious exposure-response relationship. The levels of oxygen free radical in the cells exposed to ultrafine carbon black were statistically significant increased with a concentration-dependent relationship. Conclusions UFCB may caused an oxidative damage to alveolar epithelium cell Ⅱ , which could help the particles further to penetrate into interstitial tissue of alveoli to induce more injury.