先天性食管闭锁并气管食管瘘的早期胚胎学研究

THE EMBRYOLOGICAL CHANGES OF THE ESOPHAGUS AND TRACHEA IN CONGENITAL ESOPHAGEAL ATRESIA AND TRACHEOESOPHAGEAL FISTULA

目的采用阿霉素诱导食管闭锁并气管食管瘘(esophageal atresia and tracheoesophageal fistula,EA-TEF)大鼠模型,探讨胚胎发育过程中气管、食管分化异常的发生机制以及可能的影响因素。方法 SD雌性孕鼠10只,随机分为空白对照组、模型组,每组5只;模型组于第6～9天,每日腹腔注射阿霉素2.0mg/kg,空白对照组5只SD大鼠于第11.5、12.5天,模型组5只SD大鼠于第11.5、12.5、13.5天进行取材。取材标本进行HE及PAS染色,形成纤维细胞生长因子7、10(fibroblast growth factor 7、10,FGF7,10),免疫组织化学染色。结果①模型组,11.5d标本HE染色后未见明显肺芽萌出,12.5d可见瘘管与两侧支气管类似三分叉结构,多在相同水平发生,PAS染色及FGF7、10免疫组织化学染色可见瘘管组织阳性染色,近段前肠可见喉气管憩室以远端腹侧半为阳性;②空白对照组,HE染色可见到11.5d肺芽萌出,12.5d时可见气管、食管分离,在气管、食管分离处的前肠壁内有大量凋亡小体,PAS染色以及FGF7、10免疫组织化学染色可见前肠背侧及食管表现为阴性,前肠腹侧半及气管部分为阳性。结论通过阿霉素致畸形动物模型早期胚胎学的研究可知,正常气管、食管的分隔可能与局部细胞的凋亡具有相关性;气管、食管的正常分隔可能是前肠正常发育的必须条件,FGF7、10在模型组气管食管瘘中可能存在间充质细胞的异常,产生异常的信号因子而导致气管食管瘘。

Objective To explore the process of embryonic development of the trachea and esophagus, the mechanism of abnormal differentiation and possible influencing factors through the adriamycin- induced -esophageal atresia and tracheo -esophageal fistula （EA -TEF ） rat model. Methods Ten pregnant female SD rats were randomly diviede into control group and model group with 5 rats in each group ; Model group received daily intraperitoneal injection of doxorubicin 2.0mg/kg. Rats of control group were sacrificed at 11.5d and 12.5d,and 3 rats of model group were sacrificed at 11.5d, 12.5d and 13.5d. The specimens were statined by hematoxylin and eosin （HE） and perodic acid - schiff （PAS） methods. Fibroblast growth factor 7,10 （FGF 7,10） was detected by immunohistochemistry. Results （1）In model group,HE stained specimens of 11.5d had no obvious lung bud eruption,those of 12.5d appeared fistula and bronchi no both sides similar to triple - brach, mostly occurred at the same leuel. The fistublar tissue and the distal ventral part of larynogotracheal diverticulum was positively stained by PAS and FGF 7,10 immunohistochemistry. （2）In control group, HE stained specimeas of 11.5d showed lung bud eruption,those of 12.5d appeared the septation between trachea and esophagus with lots of apoptotic bodies within the foregut wall around the septation of trachea and esophagus. The doresal part of foregnt and the esophagus was negatively stained, the ventral part of forget and the trachea was positively stained by FGF 7, 10 immunohistochemistry. Conclusion The early embryological study using adriamycin- induced EA -TEF model shows that the normal septation between trachea and esophagus may be a necessary condition for the normal development of foregut, which may be related to local cell apoptosis. The expression of FGF 7,10 may be abnormal in mesenchymal cells of TEF model group, resuhing in abnormal signaling factors, which lead to TEF.