103Pd放射性支架抑制再狭窄的作用及对平滑肌细胞凋亡基因表达的影响

目的　观察1 0 3Pd放射性支架对兔腹主动脉中膜平滑肌细胞凋亡相关基因Bcl 2及BaxmRNA表达的影响 ,探讨其防治血管成形术后再狭窄的作用机理。方法　将雄性新西兰大白兔 5 0只随机分为普通支架组及1 0 3Pd放射性支架组 ,设正常对照。分别于术后 3、7、14、2 8和 5 6d取材 ,进行病理形态学研究 ,并用原位杂交的方法测定血管中膜平滑肌细胞中Bcl 2mRNA及BaxmRNA的表达。结果　光镜下发现 ,放射性支架组管腔狭窄程度明显低于普通支架组 ,术后第 5 6天最显著(P <0 0 1)。与对照组比较 ,术后 3～ 2 8d普通支架组与放射性支架组Bcl 2mRNA表达均明显增加 ,而放射性支架组的表达则较普通支架组降低 (P <0 0 1)。BaxmRNA的表达 ,术后第 3～ 2 8天两支架组均超过对照组 ,而放射性支架组的表达较普通支架组显著增加 (P <0 0 1)。Bcl 2mRNA与BaxmRNA的比值显示 ,普通支架组术后第 3、14和 2 8天均大于对照组 (P <0 0 1) ,放射性支架组虽也大于对照组 ,但无统计学差异 (P >0 0 5 )。术后第 3～ 2 8天 ,放射性支架组的比值均小于普通支架组(P <0 0 5 )。结论　1 0 3Pd放射性支架增加细胞凋亡的BaxmRNA表达 ,减少抑制细胞凋亡的Bcl 2mRNA表达 ,使凋亡细胞比例增加 ,降低再狭窄的发生

Influence of 103Pd radioactive stent on the expression of Bcl-2 and Bax mRNA in vascular smooth muscle cells

Objective Observing the influence of ¹⁰³Pd radioactive stent on the expression of apoptosis relative genes of Bcl-2 and Bax mRNA in rabbit from tunica media of abdominal aorta arteries by ¹⁰³Pd radioactive stent after angioplasty. Methods Fifty male New Zealand rabbits were randomized into an ordinary stent (OS) group,¹⁰³Pd stent (PdS) group and a control group.The aortas were harvested on days 3,7,14,28 and 56 after operation.The pathomorphology observation was performed and the method of in situ hybridization was used to evaluate the expression of Bcl-2 and Bax mRNA. Results The severity of the stenosis in the PdS group was less severe than that of the OS group.It was most obvious on the 56th day (P<0.01).Compare with the control group,the expressions of Bcl-2 mRNA of the OS and the PdS group were all increased on days 3 to 28,but the expression in the PdS group was lower than that of the OS group.The highest expression was on the 28th day,(18.43±0.67)% vs (21.55±0.93)%(P<0.01).The expressions of Bax mRNA of the two stent groups were all over the control group on days 3 to 28,at the same time,the expression in the PdS group was more impressive than that in the OS group.The peak was noted on the 7th day,(11.17±0.94)% vs (9.30±1.01)% (P<0.01).The ratio of Bcl-2 and Bax mRNA showed that the result of the OS group was much higher than that of the control group on days 3,14 and 28(P<0.01).Although the value of the PdS group was also higher than that of the control group,there was no statistic significance(P>0.05).The ratio of the PdS group was much lower than that of the OS group on days 3 to 28(P<0.05). Conclusion ¹⁰³Pd radioactive stent increases the expression of Bax mRNA which stimulates apoptosis and decreases the expression of Bcl-2 mRNA which inhibits apoptosis,resulting in improvement of the ratio of apoptosis to proliferation and prevention of the occurrence of restenosis.