尿道内放射与Bax/Bcl-2基因表达及细胞凋亡关系的实验研究

Effect of γ-radiation from 103Pd radioactive stent on the expression of Bax/Bcl-2 and appoptosis in the urethral tissue

目的探讨103Pd支架对雄性新西兰白兔尿道组织Bax/Bcl-2基因表达的影响及与细胞凋亡的关系。方法分别将普通支架和103Pd同位素支架置入兔的尿道内,术后30d取尿道标本,采用免疫组化、Tunel方法检测尿道组织Bax/Bcl-2基因表达及细胞凋亡情况。结果放射性支架组尿道组织Bax蛋白表达明显上调,其阳性率为83.3%,明显高于普通支架组的16.7%(P﹤0.05);Bcl-2蛋白表达降低,其阳性率为33.3%,明显低于普通支架组的83.3%(P﹤0.05)。放射性支架组成纤维细胞、平滑肌细胞等凋亡明显,细胞凋亡数为161.93±26.21,尿道无明显狭窄;普通支架组细胞凋亡不明显,细胞凋亡数为65.27±13.39,尿道出现不同程度的狭窄。结论103Pd放射性支架通过增强Bax基因表达、降低Bcl-2基因表达,可促进兔尿道组织细胞凋亡,抑制尿道损伤愈合过程中管腔的再狭窄。

Objective To study the effect of T-radiation on the expression of Bax/Bcl-2 and apoptosis in the urethral tissue of male New Zealand rabbits. Methods Normal stent and ^103pd radioactive stent were implanted into the urethra of New Zealand rabbits, and the samples of urethral tissues were obtained after 30 days. The expression of Bax/Bcl-2 in the urethral tissue was determined by immunohistochemistry. The number of apoptotic cells was counted by tunel method. Results The expression of Bax protein was up-regulated and the expression of Bel-2 protein was downregulated in ^103Pd radioactive stent group.The number of apoptic cells including fibroblasts and smooth muscle cells in ^103Pd radioactive stent group（161.93±26.21） was greater than that in normal stent group（65.27±13.39）, while urethral stricture in normal stent group was more obvious than that in ^103Pd radioactive stent group. Conclusions The expression of Bcl-2 and Bax is associated with the apoptosis of cells in the urethral tissue, ^103pd radioactive stent may facilitate the apoptosis of cells in the urethral tissue and thus inhibit the urethra of stricture by increasing the expression of Bax and decreasing the expression of Bel-2.