盐酸氨溴索对大鼠膈疝模型肺发育的影响

目的 探讨盐酸氨溴索(沐舒坦)对大鼠先天性膈疝模型及其肺发育的影响及可能机制.方法 9只孕9.5 d的大鼠分为3组:对照组(2只)仅给予橄榄油灌胃,膈疝组(2只)及沐舒坦干预组(沐舒坦组,5只)给予除草醚200 mg灌胃.孕18.5、19.5、20.5 d,对照组及膈疝组分别腹腔注射生理盐水,沐舒坦组每日腹腔注射盐酸氨溴索100 mg/kg.孕21 d行剖宫产,观察各组膈疝发生率,取胎肺称重,行HE、弹力纤维EVG染色及肿瘤转化生长因子(TGF)-β1免疫组化染色,检测双肺湿重/体重、平均终末支气管密度(MTBD)、肺泡面积百分比(PLAA)、中小动脉中膜厚度百分比(MT%)和TGF-β1在肺的表达强度.结果 对照组30只子鼠无膈疝发生;膈疝组19只子鼠发生膈疝13只,沐舒坦组43只子鼠发生膈疝28只,两组间膈疝发生率差异无统计学意义(P=0.502).对照组肺发育成熟,膈疝组处于假腺体期,沐舒坦组发育居中.膈疝组双肺湿重/体重、PLAA均低于对照组[(45±6)mg/g比(60±7)mg/g,(50.1±4.0)%比(58.4±3.0)%,均P=0.001];MTBD、MT%均高于对照组[(14.0±1.8)比(8.5±1.1),(45±6)%比(29±6)%,均P=0.001];而沐舒坦组PLAA[(54.0±2.0)%]高于膈疝组(P=0.001),MTBD、MT%[12.2±2.1,(39±4)%]均低于膈疝组(P=0.006,P=0.002).膈疝组TGF-β1在肺的表达强度与对照组比较,差异有统计学意义(13 594±3113比9447±1355,P=0.001),沐舒坦组(10 015±818)低于膈疝组(P=0.01).结论 沐舒坦不影响膈疝的发生率,但在一定程度能促进膈疝大鼠胎肺发育、改善肺小动脉发育不良;抑制TGF-β1的表达、抗氧化可能是其下游的作用.

Effect of ambroxol on lung development of rat models with nitrofen-induced congenital diaphragmatic hernia

Objective To investigate the effects of ambroxol on rat models with nitrofen-induced congenital diaphragmatic hernia (CDH) and its potential mechanism.Methods Nine pregnant female SD rats were randomly divided into 3 groups at Day 9.5:2 ml olive oil intragastrically in control group (2 rats)and 200 mg nitrofen in nitrofen (2 rats) and ambroxol groups (5 rats).Antenatal ambroxol was given intraperitoneally to ambroxol group at Days 18.5,19.5 and 20.5 of gestation while control and nitrofen groups only received intraperitoneal normal saline.At Day 21.5 the fetuses were delivered by cesarean section.Incidence of hernia,lung weight/body weight (LW/BW),mean terminal branch density (MTBD),percentage of lung alvkolar area (PLAA),percentage of wall thickness (MT%) and the expression of TGF-β1 were observed.Results There were 19 CDH fetuses in nitrofen group (68.4%).The incidence of hernia in ambroxol group was 65.1% (28/43).There was no significant difference (P > 0.05)between two groups.LW/BW and PLAA decreased while MTBD and MT% increased significantly in the nitrofen group versus the control group[(45±6) mg/g vs (60±7) mg/g,(50.1±4.0) % vs (58.4 ±3.0)%,(14.0± 1.8)vs(8.5 ±1.1),(45 ±6)% vs(29 ±6)%,all P=0.001].After ambroxol intervention,the ambroxol group showed a higher PLAA but a lower MTBD and MT%[(54.0±2.0) %,(12.2±2.1),(39±4) %]than those in the nitrofen group (P=0.001,0.006,0.002).The expression of TGF-β1 in pulmonary tissues of the nitrofen group was significantly higher than that in the control group (13 594±3113 vs 9447±1355,P=0.001).It decreased after ambroxol intervention (10 015±818,P =0.01).Conclusion Though with no effect upon the occurrence of CDH in rats,the administration of ambroxol may improve the pulmonary maturity.The down-regulated expression of TGF-β1 and the oxidative stability are possible mechanisms.