全氟化碳腹腔注射对内毒素肺损伤大鼠中性粒细胞肺浸润的抑制作用

目的通过内毒素(脂多糖,LPS)导致的急性肺损伤(ALI)大鼠模型,探讨全氟化碳(perfluorocarbon,PFC,分子式为 C_8F_(18))腹腔预注射对内毒素导致 ALI 大鼠中性粒细胞(PMN)肺浸润的抑制作用。方法健康雄性 Wistar 大白鼠108只,随机分为正常对照组、PFC 对照组、LPS 组和PFC+LPS 组,每组分别在2、4、6 h 3个时间点各观察9只大鼠。行支气管肺泡灌洗,对支气管肺泡灌洗液(BALF)和血液进行白细胞计数和 PMN 分类,对病理组织进行 PMN 计数,免疫组化检测肺组织E-选择素和胞间黏附分子1(ICAM-1)。结果 (1)LPS 组 BALF 在2、4、6 h 白细胞计数分别为(1.98±0.21)、(2.98±0.43)(3.95±0.29)×10~6/L,PMN 分类分别为0.170±0.069、0.250±0.046、0.351±0.054,均较正常对照组升高[白细胞计数分别为(1.27±0.20)、(1.27±0.18)、(1.26±0.11)×10~6/L,PMN 分类分别为0.041±0.008、0.041±0.007、0.041±0.007,t 值为5.680～18.924,P 均<0.01],而 PFC+LPS 白细胞计数[(1.45±0.39)、(2.67±0.44)、(3.29±0.45)×10~6/L]、PNM分类(0.065±0.024、0.102±0.033、0.174±0.049)显著低于 LPS 组(t 值为-4.224～12.033,P均<0.01)。(2)与之相反,LPS 组血液白细胞计数在4、6 h 表达[(5.26±0.85)、(4.38±0.39)×10~9/L]显著低于正常对照组[(6.29±0.55)、(6.28±0.60)×10~9/L,t 值为-3.088、-7.946,P 均<0.01),而 PFC 预处理后升高。(3)PFC+LPS 组的肺组织 PMN[2、4、6 h 分别为(7.56±1.81)、(18.76±3.51)、(33.99±5.68)个/视野]、E-选择素(积分吸光度值表示,2、4、6 h 分别为867±128、1 161±227、1 922±424)和 ICAM-1(积分吸光度值表示,2、4、6 h 分别为208±78、283±67、625±85)均较 LPS 组[肺组织 PMN 2、4、6 h 分别为(10.78±0.92)、(31.55±3.00)、(54.14±5.49)个/视野,E-选择素2、4、6 h 分别为1 086±256、1 606±408、3 409±1 751,ICAM-12、4、6 h 分别为299±97、378±67、817±149]降低,差异均有统计学意义(t 值为-2.400～-11.480,P 均<0.01)。结论腹腔预注射 PFC 对内毒素导致肺损伤的 PMN 肺浸润有一定的抑制作用,可能与降低肺血管内皮细胞表达E-选择素和 ICAM-1有关。

Perfluorocarbons injected intraperitoneally suppress neutrophilic infiltration in lipopolysaccharide-induced lung injury in rats

OBJECTIVE: To explore the suppressive effects of perfluorocarbon (PFC, C(8)F(18)) injected intraperitoneally on neutrophilic infiltration in lipopolysaccharide (LPS)-induced lung injury in rats. METHODS: A hundred and eight Wistar rats were randomly divided into 4 groups, and with 9 rats in each of the 3 time points respectively: Normal control group (NC group), PFC control group (PFC group), LPS-induced acute lung injury group (LPS group) and PFC pre-treatment group (PFC + LPS group). The animals were injected intraperitoneally with PFC at dose of 15 ml/kg in PFC group and PFC + LPS group 48 hours before. LPS at dose of 7 mg/kg injected via penile vein induced lung injury at LPS group and PFC + LPS group and the animals were respectively killed by exsanguination at 2, 4, 6 hour points. The white blood cells and neutrophils were counted in bronchoalveolar lavage fluid (BALF) and venous blood, and the neutrophils were counted in lung tissue under microscope. The expression of E-selectin and intercellular adhesion molecule-1 (ICAM-1) were immunohistochemically detected in lung tissue as integrated optic density (IOD) measured with Image Pro Plus 5.1 software. RESULTS: (1) The counts of white blood cells of BALF [(1.98 +/- 0.21), (2.98 +/- 0.43), (3.95 +/- 0.29) x 10(6)/L at three times points respectively] and PMN percentages (0.170 +/- 0.069, 0.250 +/- 0.046, 0.351 +/- 0.054 at times points respectively) in LPS group significantly increased as compared with those in NC group [(1.27 +/- 0.20), (1.27 +/- 0.18), (1.26 +/- 0.11) x 10(6)/L and 0.041 +/- 0.008, 0.041 +/- 0.007, 0.041 +/- 0.007 at three times points respectively, t = 5.680 - 18.924, all P < 0.01]. The counts of white blood cells and PMN percentages of BALF in PFC + LPS group [(1.45 +/- 0.39), (2.67 +/- 0.44), (3.29 +/- 0.45) x 10(6)/L and 0.065 +/- 0.024, 0.102 +/- 0.033, 0.174 +/- 0.049 at times points respectively] significantly reduced as compared with those of LPS group (t = -4.224 - 12.033, P < 0.01). (2) On the contrary, the counts of white blood cells of venous blood in LPS group [(5.26 +/- 0.85), (4.38 +/- 0.39) x 10(9)/L at 4, 6 h] were significantly lower than NC group [(6.29 +/- 0.55), (6.28 +/- 0.60) x 10(9)/L, t = -3.088 and -7.946, P < 0.01], whereas the PFC pre-treatment significantly increased the counts. (3) In lung tissue, the counts of PMN per field (7.56 +/- 1.81, 18.76 +/- 3.51 and 33.99 +/- 5.68), the expressions of E-selectin (IOD: 208 +/- 78, 283 +/- 67 and 625 +/- 85) and ICAM-1 (IOD: 208 +/- 78, 283 +/- 67 and 625 +/- 85) in PFC + LPS group were significantly decreased compared with LPS group (10.78 +/- 0.92, 31.55 +/- 3.00 and 54.14 +/- 5.49; 1,086 +/- 256, 1,606 +/- 408 and 3,409 +/- 1,751; 299 +/- 97, 378 +/- 67 and 817 +/- 149, respectively, t = -2.400 - 11.480, P < 0.01) at three time points. CONCLUSION: PFC pre-injected intraperitoneally significantly suppressed the neutrophilic infiltration in LPS-induced lung injury and reduced the expressions of E-selectin and ICAM-1 as the possible molecular mechanism of its effects.