摘要
目的 观察呼吸机相关性肺损伤（VILI）模型大鼠肺组织中血红素加氧酶-1（HO-1）表达的变化,探讨HO-1诱导剂血晶素拮抗VILI的作用机制.方法 56只雄性SD大鼠按照随机数字表法分成对照组（C组）,VILI模型组（M组）,诱导剂血晶素1、2、3、4组（H1、 H2、H3、H4组,制模前24 h分别腹腔注射血晶素40、80、120、160 μmol/kg）和抑制剂Z组[制模前24 h腹腔注射锌原卟啉（ZnPP）10 μmol/kg].除C组外各组机械通气4 h后处死大鼠,收集支气管肺泡灌洗液（BALF）,测定总蛋白、肿瘤坏死因子-α（TNF-α）和白细胞介素-10（IL-10）含量;取肺组织,测定肺湿/干重（W/D）比值、乳酸脱氢酶（LDH）、超氧化物歧化酶（SOD）和丙二醛（MDA）水平及HO-1蛋白表达;光镜下行肺组织病理观察.结果 与C组相比,M组大鼠肺病理损伤严重,BALF中总蛋白、TNF-α、IL-10,肺组织W/D比值、MDA、LDH及HO-1蛋白表达均明显增加, VILI模型复制成功.与M组比较,随着血晶素剂量的增加,H1、H2、H3组总蛋白（g/L）显著下降（0.74±0.06、0.73±0.07、0.70±0.07比0.84±0.08,均P〈0.01）;W/D比值下降（4.93±0.27、4.91±0.24、4.87±0.23比5.53±0.48,均P〈0.01）;SOD活性（U/mg）显著升高（85±9、82±15、93±11比55±12,均P〈0.01）;MDA含量（nmol/mg）显著降低（15±3、15±3、13±2比18±4,P〈0.05或P〈0.01）;IL-10含量（pg/L）逐渐升高（0.42±0.06、0.46±0.06、0.47±0.05比0.36±0.07）,TNF-α含量（pg/L）逐渐降低（0.18±0.07、0.14±0.03、0.10±0.07比0.23±0.06）,但只有H2、H3组差异有统计学意义（均P〈0.01）;LDH活性（U/g）降低（11 353±1 317、11 516±1 613、9 631±1 520比12 361±1 841）,但仅H3组差异有统计学意义（P〈0.01）;HO-1蛋白表达[吸光度（A）值]逐渐增强（0.164±0.010、0.190±0.149、0.205±0.018比0.122±0.016,均P〈0.01）;肺病理损伤逐渐减轻.而随着剂量进一步增加,H4组肺组织损伤较H1、H2、H3组加重.给予HO-1抑制剂ZnPP后HO-1的保护作用消失.结论 血晶素诱导HO-1适度表达可以减轻VILI,其适度表达的最佳剂量为120 μmol/kg,其机制可能通过抗炎和抗氧化应激发挥对肺组织的保护作用.
Objective To observe the changes in heme oxygenase-1 （HO-1） expression in lung tissue with ventilator induced lung injury （VILI） in rats, and to explore the mechanism of preventive effect of HO-1 inducer hemin on VILI. Methods Fifty-six male Sprague-Dawley （SD） rats were randomly divided into control group （group C）, VILI model group （group M）, hemin group 1, 2, 3, 4 （group H1, H2, H3, H4, with intraperitoneal injection of hemin 40, 80, 120, 160 μmol/kg, respectively, 24 hours before model was reproduced）, and suppressor Z group （intraperitoneal injection of ZnPP 10 μmol/kg 24 hours before reproduction of the model）. After 4 hours of ventilation, all rats, except those of group C, were sacrificed, and bronchoalveolar lavage fluid （BALF） was collected. Total protein, the contents of tumor necrosis factor-α （TNF-α） and interleukin-10 （IL-10） in BALF were measured. The lung tissue specimen was collected, the wet-to-dry weight ratio （W/D）, the level of lactate dehydrogenase （LDH）, superoxide dismutase （SOD）, malondialdehyde （MDA） and HO-1 protein expression were determined. Lung pathological changes were observed with microscope. Results In group M, rat lung tissue was seriously damaged, and total protein in BALF, TNF-α, IL-10, W/D of lung, MDA and LDH activity, as well as HO-1 protein expression were markly higher than those in group C, denoting that VILI model was successfully reproduced. Compared with group M, the total protein in BALF （g/L） in group H1, H2, H3 was gradually reduced （0.74±0.06, 0.73±0.07, 0.70±0.07 vs. 0.84±0.08, all P〈0.01） with an increase in hemin dose. W/D of lung was reduced （4.93±0.27, 4.91±0.24, 4.87±0.23 vs. 5.53±0.48, all P〈0.01）. The activity of SOD （U/mg） was higher （85±9, 82±15, 93±11 vs. 55±12, all P〈0.01）, and the content of MDA （nmol/mg） was decreased （15±3, 15±3, 13±2 vs. 18±4, P〈0.05 or P〈0.01）. The content of IL-10 （pg/L） in BALF was higher （0.42±0.06, 0.46±0.06, 0.47±0.05 vs. 0.36±0.07）, and the content of TNF-α （pg/L） was decreased （0.18±0.07, 0.14±0.03, 0.10±0.07 vs. 0.23±0.06）, but only the difference between group H2, H3 and group M was statistically significant （all P〈0.01）. The activity of LDH （U/g） was decreased （11 353±1 317, 11 516±1 613, 9 631±1 520 vs. 12 361±1 841）, but only the difference between group H3 and group M was statistically significant （P〈0.01）. HO-1 expression [absorbance （A） value] was increased compared with that of group M （0.164±0.010, 0.190±0.149, 0.205±0.018 vs. 0.122±0.016, all P〈0.01）, and the degree of lung injury was reduced with increase in dosage. With the further increase of hemin dose, lung injury in group H4 was more serious than that of group H1, H2 and H3. With ZnPP to inhibit HO-1 expression, the protective effect of HO-1 disappeared. Conclusion A moderate expression of HO-1 as induced by hemin can alleviate VILI, and the best dose of hemin is 120 μmol/kg. Its protective effect on lung tissue may possibly be attributed by its anti-inflammatory effect and anti-oxidative stress.
出处
《中国危重病急救医学》
CAS
CSCD
北大核心
2010年第7期410-413,I0002,共5页
Chinese Critical Care Medicine
基金
江苏省科技厅社会发展基金（2005019）
江苏省“六大人才高峰”第六批资助项目（卫生行业200938）
