辐射诱导对犬胆管平滑肌细胞凋亡中BCL-2活性的影响

Effect of ^(125)I Radioactive Stent on Expression of BCL-2 Gene in Apoptotic Muscle Cells of Bile Duct in Dogs

目的:探讨γ射线对BCL-2基因在犬胆管壁增殖平滑肌细胞凋亡中的活性影响。方法:实验犬24只(15～18kg),随机分为普通支架组和^(125)I支架组各12只。用切断吻合法,造成胆总管损伤。术后30天胆道狭窄形成后,分组将普通支架及125I支架从胆总管末端开口处释放到胆总管内。置入支架后60d分别行病理形态学检测,用免疫组织化学方法进行凋亡细胞,BCL-2蛋白基因检测,并用计算机图像检测系统检侧两组胆管腔面积。结果:^(125)I支架组犬胆管组织中BCL-2基因表达较普通支架组减弱,且BCL-2基因低表达组犬胆管出现明显增殖平滑肌细胞凋亡,而且犬肝外胆管无明显狭窄;而普通支架BCL-2基因高表达,且犬胆管未出现增殖平滑肌细胞明显凋亡,而且犬肝外胆管有明显狭窄。结论:^(125)I放射性支架通过抑制BCL-2基因,促进犬胆管增殖平滑肌细胞凋亡,可以抑制犬肝外胆管狭窄。

Objective： To discuss the expression and significance of BCL-2 gene in the apoptotic muscle cells in γ-radiation-induced muscle cell lines. Methods： The experimental dogs were randomly divided into common stent group and 125↑I stent group, and each of 12 animals. Duct was injured with cutting-anastomosis way. After formation of duct stenosis 30 days after operation, common stents and 125↑I stents were inserted in the end of the bile common ducts of the two groups respectively. Pathohistology of the ducts were analyzed, and cell apoptosis and the expression of BCL-2 were analyzed by immunohistochemistry staining. Results： The maximum intimal thickness of bile duct in the 125↑I stent group was found to be obviously thinner than that in common stent group after 90d. The percentages of the stenosis of the bile duct were （53.72±13.89）% and （ 17,34± 9.28）%, respectively, and there was a significant difference between the two groups （P〈0.05）. The circumference and area of bile duct lumen were obviously larger than that in the common stent group （P〈0.05）. The apoptotic biliary duct smooth muscle cells [（85.5 ±7.66）/cm2 ] were more significantly increased in the 125↑I radioactive stent group than in the general stent group [（5.1 ±0.61 ）/cm^2] , P〈0.05, and we found that the expression of BCL-2 protein was obviously reduced. Conclusion： The result shows that 125↑I radioactive stent can inhibit the proliferation of biliary ductal smooth muscle cells.