全反式维甲酸对大鼠肺气肿模型的早期干预作用

Ail-trans-retinoic acid to rat emphysema model of early intervention role

目的研究全反式维甲酸（ATRA）对木瓜蛋白酶所致大鼠肺气肿模型的早期干预作用。方法采用木瓜蛋白酶气管内滴注的方法，将体质量170～220g60只SPF级SD大鼠随机分为对照组（N），模型组（R），ATRA治疗组（R1），棉籽油组（Rz）各15只。后3组向大鼠气管内滴注5％木瓜蛋白酶1ml／kg，N组同样滴注等量生理盐水，14d后，分别向R，组和R2组大鼠腹腔内连续注入1000μg／kg ATRA和棉籽油，第90天杀死全部大鼠。取出肺组织，行HE染色观察各组大鼠的肺脏的病理变化，和病理形态学图像分析了解肺气肿模型是否建立及ATRA对于木瓜蛋白酶复制的大鼠肺气肿模型的早期干预效果。行免疫组织化学染色，计算各组Ⅱ型肺泡上皮细胞（AECⅡ）凋亡率，及Bax蛋白、Bcl-2蛋白阳性细胞个数，比较各组之间AECⅡ凋亡率，及Bax蛋白、Bcl-2蛋白阳性细胞个数的差异。结果肺体积结果显示：R、R1、R2组的肺体积与N组比较，明显增大；R、R2组之间差异无统计学意义。肺泡形态学结果显示：R、R1、R2与N组比较，每个视野内的肺泡数明显减少，平均肺泡面积增大，平均内衬间隔较大，R2组相对于R组，肺泡形态学各项指标差异无统计学意义。R、R1、R2组与N组比较，大鼠肺组织AECⅡ凋亡明显增多，R1与R组比较，AECⅡ凋亡率明显下降，R2与R组比较，AECⅡ凋亡率无明显变化，R、R1、R2组在造模后肺泡壁细胞Bcl-2阳性细胞百分比显著高于N组，R组肺泡壁细胞Bcl-2阳性细胞百分比显著低于R1组，R组肺泡壁细胞Bcl-2阳性细胞百分比与R2组差异无统计学意义。R、R1、R2在造模后肺泡壁Bax蛋白阳性细胞百分比显著高于N组，R组肺泡壁细胞Bax蛋白阳性细胞百分比显著高于R1组，R组肺泡壁Bax蛋白阳性细胞百分比与R2组差异无统计学意义。R1组Bcl-2／Bax比例明显高于R、R2组，而与N组差异无统计学意义。结论ATRA治疗可降低大鼠肺气肿模型AECⅡ凋亡率，调节Bax蛋白、Bcl-2蛋白表达，对大鼠肺气肿进程起到干预作用。

Objective To study the all-trans-retinoie acid （ATRA） to be caused by papain rat emphysema model of early intervention role. Methods The papain endotracheal drip method, weight 170- 220 grams only 60 SPF SD rats randomly divided into the control group （N）, model group （R）, ATRA treatment group （R1）, cottonseed oil group （R2） the only. After the three groups to rat endotracheal drip 5 % papain, 1 ml/kg, N group also releases physiological saline drip, 14 days, separately to the treatment group and rats, cottonseed oil intra-abdominal continuous inject 1 000 μg/kg ATRA and cottonseed oil, day 90 kill all rats. Take out the lung tissue, did HE dyeing observation group of rats lung pathological changes, and pathological morphology image analysis model is established and understand emphysema ATRA for papain copy of the rats emphysema model of early intervention effect. Do immunohistochemieal stains, the calculation of the type Ⅱ aleolar epithelial cells （AEC Ⅱ ） apoptosis rate, and Bax protein, Bcl-2 protein positive cell number, comparison between groups Ⅱ AEC apoptosis rate, and Bax protein, Bcl-2 protein positive cells of the number of differences. Results The results show that the lung volume：R, R1, R2 group of lung volume and N group than in the increased obviously. R, R2 no difference between groups. The alveolar morphological results show：R, R1 , R2 group compared with N, Na significantly reduced, MAA increases, MLI bigger, R2 group compared with R group, the alveolar morphological index no obvious difference. R, R1 , R2 group compared with N, rats AEC lung tissue lI apoptosis significantly increased, R1 group compared with R, AEC Ⅱapoptosis rate decreased obviously, R2 group compared with R, AEC Ⅱ apoptosis rate no change, R, RI, R2 group made in the alveolar walls cells Bcl-2 percentage positive cells significantly higher than N group, R group of alveolar walls cells Bcl-2 positive cells percentage significantly lower than R1 group, R group of alveolar walls cells Bcl-2 percentage positive cells with R2 group there were no obvious difference. R, R1, R2 group made in the alveolar walls Bax protein positive cells percentage significantly higher than normal control group, R group of alveolar walls cells Bax protein positive cells percentage significantly higher than R1 group, R group of alveolar walls Bax protein positive ceils percentage and R2 group there were no obvious difference. R1 group Bcl-2/Bax scale was significantly higher than the R, R2 group, and had no obvious difference with N group. Conclusions ATRA treatment can reduce rat emphysema model Ⅱ AEC apoptosis rate, adjust Bax protein and Bcl-2 protein expression, to rat emphysema process have intervention role, cottonseed oil as solvent to rat emphysema process without intervention role.