| 摘要: |
| 目的 探究早期应用不同时程甲泼尼龙（MP）对大鼠烟雾吸入性肺损伤后期纤维化的改善作用。方法 178只成年雄性SD大鼠随机分为对照组（n=18）、单纯烟雾吸入组（smoke组，n=40）、烟雾吸入+MP1 d治疗组[smoke+MP（1D）组，n=40]、烟雾吸入+MP 3 d治疗组[smoke+MP（3D）组，n=40]、烟雾吸入+MP 7 d治疗组[smoke+MP（7D）组，n=40]。烟雾吸入大鼠在烟雾箱中烟雾暴露30 min以达到急性肺损伤标准，之后分别于烟雾吸入的1 d、1~3 d、1~7 d给予腹腔注射MP（每天4 mg/kg），计算大鼠28 d生存率；烟雾吸入后的第7、14、28天取大鼠肺组织行马松三色染色、天狼星红染色，并进行肺纤维化评分；通过实时荧光定量PCR测定大鼠肺组织中转化生长因子β1（TGF-β1）和α-平滑肌肌动蛋白（α-SMA）的mRNA表达；通过蛋白质印迹法测定大鼠肺组织中髓过氧化物酶（MPO）、结缔组织生长因子（CTGF）、高迁移率族蛋白1（HMGB1）、白细胞介素6（IL-6）的表达情况。结果 Smoke组大鼠烟雾吸入28 d生存率为47.50%，给予不同时程MP治疗后，生存率均提高至80%以上（P均<0.01）。马松三色染色及天狼星红染色结果显示smoke组大鼠肺纤维化程度加重，而smoke+MP（3D）组和smoke+MP（7D）组较smoke组和smoke+MP（1D）组纤维化程度改善，胶原沉积减轻（P<0.05或P<0.01）。烟雾吸入后smoke组和smoke+MP（1D）组大鼠肺组织中TGF-β1和α-SMA的mRNA表达水平逐步升高，28 d时smoke组和smoke+MP（1D）组高于smoke+MP（3D）和smoke+MP（7D）组（P<0.05或P<0.01）。烟雾吸入后28 d时smoke+MP（3D）组和smoke+MP（7D）组大鼠肺组织中MPO、CTGF、HMGB1、IL-6的表达水平低于smoke组和smoke+MP（1D）组（P<0.05，P<0.01）。但smoke+MP（3D）组和smoke+MP（7D）组上述指标差异均无统计学意义（P均>0.05）。结论 大鼠烟雾吸入后给予MP治疗可以提高其生存率，3 d或7 d的MP治疗可以改善大鼠28 d肺纤维化程度，但这两种治疗方案之间差异无统计学意义。 |
| 关键词: 烟 肺损伤 甲泼尼龙 肺纤维化 |
| DOI：10.16781/j.0258-879x.2019.01.0031 |
| 投稿时间：2018-07-20修订日期：2018-10-29 |
| 基金项目:军队后勤科研计划重点项目（BHJ16J011），解放军总医院第六医学中心创新培育基金（CXPY 201729）. |
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| Glucocorticoid attenuating pulmonary fbrosis in rats with acute lung injury induced by smoke inhalation |
| SONG Li-cheng,HAN Zhi-hai*,LI Hu-ming,MENG Ji-guang,CHEN Xu-xin,WU Jing |
(Department of Respiratory and Critical Care Medicine, Sixth Medical Center, General Hospital of PLA, Beijing 100048, China
*Corresponding author) |
| Abstract: |
| Objective To explore the effect of methylprednisolone (MP) with different durations on pulmonary fibrosis in rats with acute lung injury induced by smoke inhalation.Methods A total of 178 male SD rats were randomized into 5 groups:control group (n=18), simple smoke inhalation group (smoke group, n=40), smoke inhalation+ MP treatment for 1 d, 3 d and 7 d groups, naming smoke+MP (1D) group (n=40), smoke+MP (3D) group (n=40) and smoke+MP (7D) group (n=40), respectively. The rats were exposed to smoke for 30 min in the smoke box to meet the criteria of acute lung injury. MP (4 mg/kg per day) was injected intraperitoneally at 1 d, 1-3 d and 1-7 d after smoke inhalation. Survival rates were calculated at 28 d after smoke inhalation. At 7 d, 14 d and 28 d after smoke inhalation, the lung tissues were stained with Masson's trichrome staining and Sirius Red staining to evaluate pulmonary fibrosis. The mRNA expression levels of transforming growth factor β1 (TGF-β1) and α-smooth muscle actin (α-SMA) were detected by real-time fluorescent quantitative PCR, and the expression levels of myeloperoxidase (MPO), connective tissue growth factor (CTGF), high mobility group box 1 (HMGB1) and interleukin 6 (IL-6) were detected by Western blotting.Results The survival rate of the rats in the smoke group was 47.50%, and the survival rates were significantly improved to more than 80% after MP treatment with different durations (all P<0.01). Masson's trichrome staining and Sirius Red staining staining showed that the lung fibrosis of the rats in the smoke group was aggravated, and the fibrosis and collagen deposition in the smoke+MP (3D) and smoke+ MP (7D) groups were significantly attenuated compared with the smoke and smoke+MP (1D) groups (P<0.05 or P<0.01). As time progressed, the mRNA expression levels of TGF-β1 and α-SMA after smoke inhalation were increased in the smoke and smoke+MP (1D) groups. At 28 d after smoke inhalation, the TGF-β1 and α-SMA mRNA levels were significantly higher in the smoke and smoke+MP (1D) groups compared with the smoke+MP (3D) and smoke+MP (7D) groups (P<0.05 or P<0.01). At 28 d after smoke inhalation, the protein expression levels of MPO, CTGF, HMGB1 and IL-6 were significantly reduced in smoke+MP (3D) and smoke+MP (7D) groups compared with the smoke and smoke+MP (1D) groups (P<0.05, P<0.01). However, the above indicators have no significant difference between smoke+MP (3D) group and smoke+MP (7D) group (all P >0.05).Conclusion MP can significantly improve survival rate of rats with smoke inhalation injury. MP treatment for 3 d or 7 d can significantly attenuate smoke inhalation induced pulmonary fibrosis at 28 d after smoke inhalation, but there is no significant difference between these two treatment protocols. |
| Key words: smoke lung injury methylprednisolone pulmonary fibrosis |
