大鼠原位和异位小肠移植慢性排斥反应模型的制作与比较

目的  比较大鼠原位和异位小肠移植慢性排斥反应模型的建模效果。方法  采用F344(RT1^1vr)大鼠作为供体, Lewis (RT1¹)大鼠作为受体, 构建异系异位和原位大鼠小肠移植模型(各8只), 术后0~14 d给予皮下注射环孢素。观察术后受体的体质量变化及存活时间。采用苏木素-伊红(HE)染色观察肠组织病理学变化, 酒精苏木素染色后观察肠组织胶原纤维和弹性纤维的变化。计算两组受体大鼠的成模率。结果  异位和原位小肠移植大鼠均能长期存活, 大部分超过90 d。原位小肠移植组大鼠术后第3日恢复正常饮食, 于术后14 d左右体质量可恢复至术前水平, 之后缓慢增长, 但大部分原位小肠移植大鼠在术后150 d出现持续的体质量下降, 且不能被环孢素逆转。异位小肠移植组大鼠术后第1日恢复进食, 于术后25~30 d才能恢复至术前的体质量水平, 术后30~90 d期间, 体质量逐渐上升并保持在较高水平。原位小肠移植组大鼠术后90 d的小肠组织未出现慢性排斥反应的病理学改变且未见明显纤维化, 术后163 d和术后200 d的小肠组织出现慢性排斥反应的病理学改变, 且出现移植小肠系膜纤维化。异位小肠移植组大鼠术后90 d和术后200 d的小肠组织均出现典型的慢性排斥反应的病理学改变和移植小肠系膜纤维化。异位小肠移植组全部出现特征性病理改变, 成模率为100%, 与原位小肠移植组成模率75%比较, 差异无统计学意义(P > 0.05)。结论  应用F344→Lewis大鼠组合建立原位和异位小肠移植模型, 术后给予小剂量环孢素, 均可在术后不同时间点出现慢性排斥反应。与原位大鼠小肠移植模型相比, 大鼠异位小肠移植模型建模操作简单, 慢性排斥反应成模时间较短, 病理改变程度相对一致, 更适合用于实验研究。

Manufacture and comparison of chronic rejection model of orthotopic and heterotopic intestinal transplantation in rats

Objective To compare the modeling effect of chronic rejection following orthotopic and heterotopic intestinal transplantation in rats. Methods F344 (RT11vr) rats were used as the donors and Lewis (RT11) rats were used as the recipients. Models of allogeneic heterotopic and orthotopic intestinal transplantation in rats (8 rats in each model) were established, and subcutaneous injection of ciclosporin was given at 0~14 d after operation. Changes in body weight and survival time of the recipients were observed after operation. In addition, pathological changes in intestinal tissue were observed by hematoxylin-eosin (HE) staining. Changes in collagenous fibers and elastic fibers in intestinal tissue were observed after alcohol and hematoxylin staining. Finally, success rate of modeling of recipients in two groups was calculated. Results Rats in heterotopic and orthotopic intestinal transplantation groups were able to survive for a long time, most of which were more than 90 d. For the rats in orthotopic intestinal transplantation group, normal diet could be recovered at the 3rd d after operation. Their body weight could recover preoperative level at about the 14th d after operation, and then grew slowly. However, most of the rats in orthotopic intestinal transplantation group continued weight loss from the 150th d after operation, which could not be reversed with ciclosporin. For the rats in heterotopic intestinal transplantation group, normal diet could be recovered at the 1st d after operation, and their body weight could recover preoperative level within 25-30 d after operation and gradually rose and remained at a high level within 30-90 d after operation. No pathological changes of chronic rejection and obvious mesangial fibrosis in intestinal tissue were observed at the 90th d after operation, but intestinal tissue developed chronic rejection and obvious mesangial fibrosis at the 163rd d and 200th d after operation in orthotopic intestinal transplantation group. Typical pathological changes of chronic rejection and mesangial fibrosis in intestinal tissue were observed at the 90th d and 200th d after operation for rats in heterotopic intestinal transplantation group. All the rats in heterotopic intestinal transplantation group showed characteristic pathological changes. The success rate of modeling was 100% in heterotopic intestinal transplantation group, which was not of statistical significance, compared with the success rate of modeling of 75% in the orthotopic intestinal transplantation group(P > 0.05). Conclusions Chronic rejection will occur at different time points with small dose of ciclosporin after operation if models of orthotopic and heterotopic intestinal transplantation are established in combination of F344→Lewis rats. Compared with orthotopic intestinal transplantation, the rat model of heterotopic intestinal transplantation holds the advantages of simple modeling, shorter chronic rejection and relatively consistent degree of pathological changes, which is more suitable for experimental study.