缺血再灌注对在体兔窦房结细胞Fas-L Bax Bcl-2基因表达的影响

Ischemia reperfusion influences the protein expression of apoptosis-related genes Fas-L,Bax and Bcl-2 in sinoatrial node cells of rabbits in vivo

目的 :探讨缺血再灌注对在体兔窦房结细胞Fas L、Bax、Bcl 2表达的影响。方法 :取家兔 90只 ,随机分为对照组、缺血 10、3 0、60、12 0min组及缺血 10、3 0、60、12 0min再灌注 4h组 ,每组 10只。通过结扎及放松右冠状动脉起始部制作在体兔窦房结细胞缺血再灌注损伤模型 ,当达各预定时间点后 ,迅速切取窦房结组织 ,用SABC免疫组化法检测窦房结细胞Fas L、Bax及Bcl 2表达 ,用Tiger 92 0图象分析系统计算Fas L、Bax、Bcl 2表达平均光密度值。结果 :1 缺血 10min组窦房结细胞Fas L、Bcl 2表达与对照组比较无明显差异 ,而Bax表达则较对照组明显增强 (P <0 0 5 ) ;Fas L、Bax表达量随缺血时间延长逐渐增加 ,以缺血 12 0min组表达最强 ;Bcl 2表达则以缺血 60min组最强。 2 缺血再灌注组 ,Fas L、Bax表达随缺血时间延长逐渐增加 ,以缺血 60min再灌注 4h组最强 ;Bcl 2表达以缺血 3 0min再灌注 4h组最强 ,而缺血 12 0min再灌注 4h组已恢复至对照组水平。 3 随缺血时间延长 ,缺血组及缺血再灌注组Bcl 2 Bax比值均逐渐减小 ,而缺血再灌注组Bcl 2 Bax比值均较相同时间缺血组明显降低。结论 :缺血及缺血再灌注均可上调窦房结细胞Fas L、Bax表达 ,下调Bcl 2 Bax比值 ,此作用可能介导了缺血再灌注诱导窦房结细胞?

Objective:To study the influence of ischemia reperfusion (IR) on the expression of apoptosis- related genes Fas-L,Bax and Bcl-2 in sinoatrial node(SAN) cells of rabbits in vivo.Method:Ninety healthy adult rabbits were divided randomly into control group,ischemia groups (I) 10 (I 10min),30(I 30min),60(I 60min) or 120 min(I 120min) and IR groups (10,30,60 or 120 min ischemia followed by 4 h reperfusion respectively) (I 10minR 4h,I 30minR 4h,I 60minR 4h or I 120minR 4h).In 60 both the control group and each subgroup there were 10 rabbits.IR injury model of SAN was established by occluding and loosening the start section of right coronary artery.The rabbits were decapitated and the tissue of SAN was excised quickly at different time points.The expression of Fal-L,Bax and Bcl-2 of SAN cells was detected by SABC immunohistochemistry.Average light density values of the expression of Fas-L,Bax and Bcl-2 were determined by Tiger 920 image analysis system.Result:1.The expression of Fas-L and Bax in SAN cells of I 10min group had no significant difference compared with that of the control group.But the expressio of Bax increased significantly (P<0.05).The expression of Fas-L and Bax increased in a time-dependent manner.In ischemic group,the highest expression of Fas-L and Bax was observed in I 120min group and that of Bcl-2 was in I 60min group.2.In IR group,the expression of Fas-L and Bax was increased as the ischemic time increased.The highest expression of Fas-L and Bax was observed in I 60minR 4h group.The peak level of Bcl-2 was observed in I 30minR 4h group and the expression of Bcl-2 recovered to the level of control group in I 120minR 4h group.3.The ratio of Bcl-2 to Bax was reduced gradually in I and IR groups as the prolongation of ischemic time,and the ratio was significantly lower in IR group than in I group at the same time point.Conclusion:I and IR can up-regulate the expression of Fas-L and Bax and down-regulate the ratio of Bcl-2 to Bax in SAN cells,which may mediate the IR injury induced apoptotic process in SAN cells during ischemia reperfusion.