新生儿坏死性小肠结肠炎模型致肠外多器官时序性病理损伤

Parenterally multi-organ sequential pathological injury caused by NEC model

目的:探讨新生儿坏死性小肠结肠炎(necrotizing enterocolitis,NEC)模型肺、肝、肾的病理变化以及凋亡因子Bax、增殖细胞核抗原(Proliferating cell nuclear antigen,PCNA)、血小板活化因子(platelet-activating factor,PAF)表达与时间和程度的关系。方法:将新生SD大鼠随机分为观察组和对照组,每组70只。观察组2次/d连续3 d给予缺氧,冷刺激加人工喂养处理,对照组不设处理。建模后第1 d、第2 d、第3 d、第4 d、第5 d、第6 d、第7 d,每组各处死10只动物,均取结肠、回肠末段、肺、肝、肾行病理学检查。采用免疫组织化学法检测肺、肝和肾组织中PCNA、BCL2相关X基因(BCL2 associated X,Bax)、PAF的表达。结果:建模后第1 d动物肺、肝和肾均为炎性损伤性改变,第5 d动物肺、肝和肾损伤分别较第1和3 d时减轻,第7 d时动物炎性改变基本吸收;相较于对照组,观察组中Bax在肝和肾中凋亡较明显,肺中凋亡时间变长;PCNA在肺、肝和肾表达均升高;PAF在肺和肝中增高,肾中的变化不大。结论:NEC后会引起肺、肝和肾不同程度继发性损伤,且修复程度和时间不同,总体在建模后第4 d器官修复起主导作用。

Objective： To explore the relationship between the pathological change of lung,liver and kidney,the changes of Bax,proliferating cell nuclear antigen（ PCNA） and platelet-activating factor（ PAF） in model of necrotizing enterocolitis（ NEC） in neonatal infants. Methods： 140 neonatal Sprague-Dawley rats were randomly divided into 2 groups,with 70 rats in each group. NEC model group was established with following treatments,including artificial feeding,hypoxia（ 2 times / d for 3d） and cold stimulation. From the 1st day to the 7th day after modeling,10 rats were sampled in each group for pathological examination in the terminal ileum,colon,lung,liver and kidney tissue. The levels of Bax,PCNA and PAF were investigated by immunohistochemistry. Results： On the 1st day,the lung,liver and kidney showed inflammatory damage. On the 5th day,inflammatory injury in lung,liver and kidney was decreased when compared to the 1st and 3th day. The inflammatory injury practically disappeared on the 7th day. Compared with the control group,Bax in liver and kidney showed marked apoptosis and apoptosis time increased in lung.PCNA indicated higher degree in lung,liver and kidney. The expression of PAF in lung and liver was increased,while no remarkable changes were in kidney. Conclusions： NEC can lead to secondary injury of different degrees in lung,liver and kidney,and the degree and time of injury and repair were different. In general,organ repairing played a leading role in the 4th day after modeling.