大鼠肝缺血预处理过程中诱导型一氧化氮合酶的转录及表达

目的 :研究大鼠肝脏缺血预处理 (IP)过程中肝脏诱导型一氧化氮合酶 (NOS2 )转录及表达的改变 ,以探讨大鼠肝脏IP过程中NO合成通路的作用及意义。方法 :131只SD大鼠随机分为缺血再灌注 (I/R)组 (5 2只 )、IP组 (4 1只 )及假手术 (S)组 (38只 ) ,术后 2h ,2 4h及 1周时检测血浆NO浓度及肝组织NOS2的转录及表达。结果 :①血浆NO浓度 :IP组在术后 2h ,2 4h ,1周时均升高 ,均显著高于S组 (P <0 .0 5 ,P <0 .0 1,P <0 .0 1) ,于 2h及2 4h时均显著高于I/R组 (均P <0 .0 1) ;I/R组在 2h时显著低于S组 (P <0 .0 5 ) ,2 4h与S组无统计学差异 (P >0 .0 5 ) ,1周时显著高于S组 (P <0 .0 5 )。②肝脏NOS2的转录 :IP组在 2h及 2 4h时较I/R组显著增强 (均P <0 .0 5 ) ,1周后差异无显著性 (P >0 .0 5 )。③肝脏NOS2的表达 :在 2h及 2 4h时IP组均显著高于I/R组及S组 (均P<0 .0 5 ) ,I/R组与S组之间差异不显著 (P >0 .0 5 ) ;1周时 ,IP组及I/R组呈弱阳性表达 ,两组间差异不显著 (P >0 .0 5 ) ;S组NOS2显色呈阴性。结论 :大鼠肝脏IP过程中NOS2的转录及表达增强 ,其高转录与表达时相的提前可能与IP的早期保护效应有关。

Expression and transcription of inducible nitric oxide synthase in the liver ischemic preconditioning in rats

Objective To investigate the changes in transcription and expression of inducible nitric oxide synthase (NOS2) in the liver ischemic preconditioning (IP), and to determine the role of nitric oxide (NO) synthetic pathway in the liver IP in rats. Methods We randomly divided 131 Sprague Dawley rats into 3 groups: ischemia/reperfusion (I/R)group (n=52), IP group (n=41) , and sham operation (S) group (n=38). Plasm NO concentration and the transcription and expression of NOS2 were detected 2 hours, 24 hours, and 1 week after the operation. Results ①In the IP group, the NO concentrations at the 2 nd hour, the 24 th hour, and 1 week were significantly higher than those in the S group (P<0.05, P<0.01, P<0.01, respectively) and the NO concentrations at the 2 nd hour and the 24 th hour were obviously higher than those in I/R group (all P<0.01).In the I/R group, the NO concentration at the 2 nd hour was significantly lower than that in the S group (P<0.05);there was no significant difference between the I/R group and the S group 24 hours after the operation (P> 0.05),and the NO concentration 1 week after the operation was obviously higher than that in the S group (P< 0.05).②In the IP group, the transcription of NOS2 2 and 24 hours after the operation were significantly increased compared with that in the I/R group (all P<0.05), but after 1 week, the transcription was not statistically different between the IP group and the I/R group (P>0.05). ③In the IP group, the expressions of NOS2 after 2 and 24 hours were obviously higher than those in the I/R group (P< 0.05) and the S group (P<0.05),but the expression between the I/R group and the S group was not significantly different (P>0.05); after 1 week, the expressions of NOS2 in IP group and I/R group were weakly positive (P>0.05), and those in S group were negative(P>0.05).Conclusion The transcription and the expression of liver NOS2 increase after the liver received ischemic preconditioning in rats. That the peak phases of transcription and expression of NOS2 are ahead of time may be related to the early protective effect of the liver IP.