大鼠胆道闭锁模型99Tcm-MIBI肝胆显像特点及与肠道组织P-糖蛋白表达的相关性

Characteristics of ^99Tc^m-MIBI hepatobiliary scintigraphy in biliary atresia model and its association with the expression of P-glycoprotein in intestinal tissues

目的 建立大鼠肝外胆道闭锁模型，观察其99Tcm-MIBI肝胆动态显像变化特点及与P-糖蛋白表达的相关性。方法 取SD大鼠12只，按随机数字表法分为正常对照组（3只）和胆总管结扎组（9只）。采用胆总管双重结扎术构建大鼠肝外胆道闭锁模型。正常对照组及胆总管结扎组（结扎后2、3、4周）行99Tcm-MIBI肝胆动态显像，以3 min/帧连续动态采集30 min，并在30 min，1、2、3 h后行延迟平面显像。显像结束后取血并处死，检测血清ALT、AST、TBIL、DBIL、IBIL、γ-GT、ALP及TBA水平；取十二指肠、空肠、回肠、结肠和盲肠等部分肠段，进行P-糖蛋白的免疫组织化学检测。对数据进行两样本t检验和单因素方差分析。结果 在胆总管结扎组中，血清ALT、AST、TBIL、DBIL、IBIL、ALP、γ-GT、TBA均明显升高（t＝－3.04～－44.54，均P〈0.05）；99Tcm-MIBI显像结果示，注药后3 h结肠或盲肠区域出现放射性浓聚，而十二指肠、空肠和回肠区域未见放射性浓聚。免疫组织化学检测结果示，随着梗阻时间的延长，十二指肠、空肠和回肠肠段P-糖蛋白表达水平逐渐减弱（F＝5.17、9.07和23.52,均P〈0.05），而结肠和盲肠肠段P-糖蛋白表达水平变化不明显（F＝2.00、3.17,均P〉0.05）。结论 99Tcm-MIBI可经肠黏膜分泌进入肠腔，该分泌过程与P-糖蛋白表达水平有关。

Objective To establish rat models of extrahepatic biliary atresia, and to observe the characteristics of 99Tcm-MIBI hepatobiliary scintigraphy and evaluate its association with the expression P-glycoprotein （P-gp） in intestinal tissues.Methods A total of 12 SD rats were randomly divided into the normal control group （3 rats） and the group of common bile duct ligation （CBDL; 9 rats）. CBDL was used to establish the rat model of extrahepatic biliary atresia. 99Tcm-MIBI hepatobiliary scintigraphy was performed at 2, 3 and 4 weeks after ligation in the CBDL group and normal control group with continuous dynamic acquisition （3 min/frame） for 30 min and then delaying imaging at 30 min, 1, 2 and 3 h. After that, all rats were sacrificed, and the blood samples were taken out for the determination of serum ALT, AST, TBIL, DBIL, IBIL, ALP, γ-GT and TBA, and the tissues of duodenum, jejunum, ileum, colon and cecum were taken out for analyzing the expression level of P-gp by immunohistochemistry. Two-sample t test and one-way analysis of variance were used.Results Compared with the normal control group, the serum levels of ALT, AST, TBIL, DBIL, IBIL, ALP, γ-GT and TBA were significantly increasing at 2, 3, 4 weeks after ligation in CBDL group （t： -3.04 to -44.54, all P〈0.05）. 99Tcm-MIBI hepatobiliary imaging showed that there was radioactive accumulation in colon or cecum area, excluding the duodenum, jejunum and ileum area, at 3 h after intravenous injection of 99Tcm-MIBI in CBDL group. The results of immunohistochemistry showed that with the obstruction time prolonged, the expression levels of P-gp in duodenum, jejunum and ileum segments were gradually decreased （F=5.17, 9.07, 23.52; all P〈0.05）, while the expression levels in the colon and cecum segments were not changed obviously （F=2.00, 3.17; both P〉0.05）.Conclusion 99Tcm-MIBI can be excreted through intestinal mucosa, and this process may be associated with P-gp expression.