博来霉素诱导大鼠与小鼠肺纤维化模型的评价

Comparison and evaluation of different doses of bleomycin⁃induced pulmonary fibrosis models in mice and rats

目的 采用一次性气管滴注不同剂量博来霉素诱导大、小鼠肺纤维化模型,明确其适宜造模剂量,并比较大、小鼠模型特征。方法 将30只SD大鼠随机分为空白组、博来霉素低剂量组(3 mg/kg, BL-L组),博来霉素高剂量组(5 mg/kg, BL-H组),每组各10只,30只C57BL/6J小鼠分组同上。观察动物每日精神、饮食等一般情况及每周体重变化,通过非束缚小动物肺功能测量仪检测动物的潮气量(tidal volume, TV)、每分钟通气量(minute ventilation, MV)、50%潮气量呼气流量(50%tidal volume expiratory flow, EF50),采用HE和Masson染色法观察肺组织病理学改变,采用羟脯氨酸(hydroxyproline, HYP)含量检测试剂盒测定肺组织羟脯氨酸含量。结果 (1)存活率和体重C57BL/6J小鼠BL-L组和BL-H组存活率分别为70%、80%,SD大鼠分别为70%、50%。第7天起,C57BL/6J小鼠BL-H组体重显著下降(P<0.05,P<0.01),SD大鼠BL-L组和BL-H组体重均显著下降(P<0.01)。(2)肺功能与空白组比较,第10天,SD大鼠两剂量组TV均降低(P<0.01),而C57BL/6J小鼠未见显著变化;第21天,SD大鼠BL-L组肺功能TV和MV显著下降(P<0.05,P<0.01),BL-H组TV显著下降(P<0.01),C57BL/6J小鼠两剂量组TV、MV和EF50均显著下降(P<0.05,P<0.01)。(3)肺病理和羟脯氨酸含量第21天,C57BL/6J小鼠和SD大鼠BL-L组和BL-H组肺组织均出现炎性浸润和纤维条索,肺泡炎和纤维化程度评分均显著升高(P<0.01),肺组织中HYP水平均显著升高(P<0.05,P<0.01)。结论 博来霉素3 mg/kg与5 mg/kg均可诱导大、小鼠肺纤维化模型。综合存活率、肺功能、肺病理等各项指标,认为C57BL/6J小鼠的适宜造模剂量为5 mg/kg, SD大鼠的适宜造模剂量为3 mg/kg。

Objective To determine the appropriate dose of bleomycin to induce pulmonary fibrosis in rat and mice models via a single intratracheal instillation and to compare model characteristics.Methods Thirty SD rats were randomly divided into blank group,bleomycin low⁃dose group(3 mg/kg,BL⁃L group),bleomycin high⁃dose group(5 mg/kg,BL⁃H group),10 in each group,and 30 C57BL/6J mice were grouped as above.The animals’general condition and body weight changes were observed.The tidal volume(TV),minute ventilation(MV),and 50%tidal volume expiratory flow(EF50)of rats and mice were measured with an animal lung function instrument.HE and Masson’s staining were used to observe histological changes to the lung tissues.Lung collagen content was measured with a hydroxyproline(HYP)kit.Results In the BL⁃L and BL⁃H groups,the survival rates of C57BL/6J mice were 70%and 80%and those of SD rats were 70%and 50%,respectively.From day 7,there was a significant decrease in the body weight of C57BL/6J mice in the BL⁃H group(P<0.05,P<0.01)and SD rats in the BL⁃L and BL⁃H groups(P<0.01).Compared with the blank group,TV was decreased in SD rats in both dose groups(P<0.01)on day 10,but no significant change was observed in C57BL/6J mice.On day 21,lung function TV and MV were significantly decreased in the BL⁃L group rats(P<0.05,P<0.01);TV was significantly decreased in the BL⁃H group rats(P<0.01);and TV,MV,and EF50 were significantly decreased in C57BL/6J mice in both dose groups(P<0.05,P<0.01).In the lung tissues of C57BL/6J mice and SD rats in the BL⁃L and BL⁃H groups on day 21,inflammatory infiltration and fibrous cords appeared,alveolitis and fibrosis degree scores were significantly increased(P<0.05,P<0.01),and HYP levels were significantly increased(P<0.05,P<0.01).Conclusions Both 3 mg/kg and 5 mg/kg bleomycin induced pulmonary fibrosis models in rats and mice.Based on survival rate,lung function,lung pathology,and other indicators,the optimal dose for C57BL/6J mice was 5 mg/kg and that for SD rats was 3 mg/kg.