探讨新生SD大鼠高氧暴露后肺泡内白细胞介素(IL)-8及肿瘤坏死因子(TNF)-α的含量变化。

选择100只生后24 h的足月、健康SD大鼠为研究对象，按照随机数字表法，将其分为高氧组(n＝50)及空气组(n＝50)。高氧组大鼠持续吸入浓度≥95%的氧气，空气组大鼠置于空气中，并于给氧后第1、3、6、10、14天，每组每次各取10只大鼠进行肺泡灌洗，应用双抗体夹心酶联免疫吸附测定(ELISA)法检测肺泡灌洗液中IL-8及TNF-α含量。统计学比较两组新生SD大鼠肺泡灌洗液中IL-8及TNF-α含量差异，以及高氧组大鼠上述不同时间点IL-8及TNF-α含量差异。两组大鼠性别构成比及出生体重比较，差异无统计学意义(P>0.05)。实验过程中对动物的处置符合动物伦理学标准。

①高氧组大鼠在高氧暴露第14天出现生长迟缓，呆滞，体重不增，呼吸浅快，口唇发绀等不良表现。②高氧组新生SD大鼠第3、6、10、14天肺泡灌洗液中IL-8含量较空气组高[(262.4±12.5)×10^－15 g/L vs (94.0±12.5)×10^－15 g/L，(374.1±14.8)×10^－15 g/L vs (94.8±7.2)×10^－15 g/L，(345.7±17.5)×10^－15 g/L vs (94.5±4.3)×10^－15 g/L，(295.5±26.6)×10^－15 g/L vs (95.6±7.5)×10^－15 g/L]，且差异有统计学意义(t＝36.909、58.033、43.981、22.878，P<0.05)；高氧组新生SD大鼠第1、3、6、10、14天肺泡灌洗液中TNF-α含量较空气组高[(43.0±4.5)×10^－15 g/L vs (29.9±1.7)×10^－15 g/L，(59.3±7.0)×10^－15 g/L vs (33.3±4.1)×10^－15 g/L，(55.1±7.7)×10^－15 g/L vs (31.1±2.5)×10^－15 g/L，(43.2±5.1)×10^－15 g/L vs (31.2±3.4)×10^－15 g/L，(34.4±3.8)×10^－15 g/L vs (30.7±2.8)×10^－15 g/L]，且差异有统计学意义(t＝－6.287、－10.190、－7.358、－2.508、－4.516，P<0.05)。③高氧组新生SD大鼠肺泡灌洗液中IL-8含量于第6天均分别较第1、3、10、14天高(t＝－50.812、－18.265、－3.910、－8.170，P<0.05)，第10天较第14天高(t＝－4.987，P<0.05)，且差异均有统计学意义；高氧组新生SD大鼠肺泡灌洗液中TNF-α含量于第3天均分别较第1、6、10、14天高(t＝－6.209、－3.719、－5.900、－9.974，P<0.05)，第6天及第10天分别较第14天高(t＝－4.416、4.732，P<0.05)，且差异均有统计学意义。

IL-8和TNF-α可能参与新生SD大鼠高氧肺损伤的早期炎症反应。

To explore the variation of interleukin(IL)-8 and tumor necrosis factor(TNF)-α contents in pulmonary alveoli of neonatal SD rats with hyperoxia exposed.

A total of 100 Sprague-Dawley(SD) rats which were healthy and 24 h after birth, were chosen as study objects. They were randomly divided into hyperxia group and air group, and 50 rats in each. Neonatal SD rats in hyperxia group were exposed to the oxygen concentration over or equal to 95%, while neonatal SD rats in air group were raised normally in air. Ten neonatal SD rats in each group were sacrificed at the 1st, 3rd, 6th, 10th and 14th day after oxygen expose, and underwent alveolar wash. The contents of IL-8 and TNF-α in the bronchoalveolar lavage fluid were detected by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA). The differences of IL-8 and TNF-α contents in the bronchoalveolar lavage fluid between two groups of neonatal SD rats, and the differences of IL-8 and TNF-α contents among different time points above mentioned in hyperxia group were statistically compared.There were no significant differences between two groups of neonatal SD rats in gender constituent ratio and birth weight (P>0.05). The disposition of the animals in experimental process was in accordance with the ethical standard of animals.

①Neonatal SD rats in hyperxia group had some bad performances on 14th day of hyperoxia expose, such as growth retardation, sluggishness, weight gain stopped, rapid and shallow breathing and cyanosis of oral lips, etc.. ②The contents of IL-8 in the bronchoalveolar lavage fluid of neonatal SD rats on 3rd, 6th, 10th, 14th days in hyperxia group were higher than those of air group[(262.4±12.5)×10^-15 g/L vs (94.0±12.5)×10^-15 g/L, (374.1±14.8)×10^-15 g/L vs (94.8±7.2)×10^-15 g/L, (345.7±17.5)×10^-15 g/L vs (94.5±4.3)×10^-15 g/L, (295.5±26.6)×10^-15 g/L vs (95.6±7.5)×10^-15 g/L], and the differences were statistically significant(t=36.909, 58.033, 43.981, 22.878; P<0.05). The contents of TNF-α in the bronchoalveolar lavage fluid of neonatal SD rats on 1st, 3rd, 6th, 10th, 14th days in hyperxia group were higher than those of air group[(43.0±4.5)×10^-15 g/L vs (29.9±1.7)×10^-15 g/L, (59.3±7.0)×10^-15 g/L vs (33.3±4.1)×10^-15 g/L, (55.1±7.7)×10^-15 g/L vs (31.1±2.5)×10^-15 g/L, (43.2±5.1)×10^-15 g/L vs (31.2±3.4)×10^-15 g/L, (34.4±3.8)×10^-15 g/L vs (30.7±2.8)×10^-15 g/L], and the differences were statistically significant(t=-6.287, -10.190, -7.358, -2.508, -4.516; P<0.05). ③The IL-8 content in bronchoalveolar lavage fluid of neonatal SD rats on 6th day in hyperxia group was higher than that of 1st, 3rd, 10th, 14th day, respectively(t=-50.812, -18.265, -3.910, -8.170; P<0.05), that of 10th day was higher than that of 14th day(t=-4.987, P<0.05), and all the differences above were statistically significant. The TNF-α content in bronchoalveolar lavage fluid of neonatal SD rats on 3rd day in hyperxia group was higher than that of 1st, 6th, 10th, 14th day, respectively(t=-6.209, -3.719, -5.900, -9.974; P<0.05), those of 6th and 10th days were both higher than that of 14th day(t=-4.416, 4.732; P<0.05), and all the differences above were statistically significant.

The IL-8 and TNF-α may participate in the prophase inflammatory reaction when hyperoxia-induced lung injury occurred in neonatal SD rats.