CT扫描在博莱霉素诱导的大鼠肺损伤研究中的应用

Experimental CT scans assessment of bleomycin-induced lung injury in the rat.

目的观察博莱霉素(BLM)诱导的大鼠肺损伤和甲基强的松龙(MPD)治疗后的双肺病理变化,研究CT扫描在大鼠肺损伤实验中的应用。方法将48只Wistar大鼠分为对照组(control)、BLM组和MPD组,control组一次性支气管内注入生理盐水02ml/100g体重;其他两组大鼠注入等容积BLM5mg/kg体重,MPD组按125mg/(kgd)MPD腹腔注射给药。三组动物分别在第3、28天取8只进行双肺CT扫描,然后做动脉血气分析,测定肺系数、肺通透指数和肺胶原含量,对肺组织进行HE染色。结果第3天BLM组肺湿重和肺系数增加,肺通透指数增高,肺组织严重水肿和充血;MPD组水肿和实变较BLM组轻;CT扫描显示BLM组大鼠肺门周围阴影密度增高,MPD组阴影的范围较小、密度减低。第28天BLM组肺组织形成肉芽肿样实变,MPD组的实变面积小于BLM组,CT扫描显示BLM组大鼠肺组织呈现致密网状/蜂窝状高密度阴影,为典型纤维化改变;MPD组的阴影密度和范围轻于BLM组。结论CT影像可以区别肺组织炎性实变和纤维化性增生,而且可以用于大鼠实验性肺损伤程度的评价。

Objective:To observ the pathological changes from bleomycin-induced lung injury in rat and the effect of methlpredinisolone(MPD),to explore the value of CT scan in the experiment of rat.Methods:48 Wistar rats were randomly divided into three groups:control,bleomycin(BLM)and MPD groups with 16 rats in each group.Each group was divided into 2 subgroups based on time of study(3,28-days).After intratracheal administration of bleomycin( 5 mg /kg)for BLM,MPD groups and physiological saline for control group, the MDP group was treated by MPD of 12 5 mg/(kg·day) each rat.At first,CT scans were used to determine for rat lung density at the day of the third and 28 th.Then analysis of blood gas,the lung coefficient,the exponent of lung penetration,the content of collagen was measures and performed.Results:In BLM group,the OW/BW and the index of lung penetration was increased and the morphology showed consolidation of oedema and congestion in lung in third day. Meanwhile,the CT scan demonstrated higher density of lung in BLM group than control group,while the density of MPD group better than BLM group with small area around hilum of lung.In 28 th day,the histology showed granuloma consolidation changes which was a typical image change of fibrosis.The scope of granuloma in MPD group was smaller than BLM group.CT scan images showed cord or net like high density spreaded wildly in lung of BLM group.The density was lighter and scope smaller in MPD than in BLM.Conclusions:CT scan can distinguish the pathological changes of inflammation and granuloma,and also evaluation of experimental lung injury in rat.