大鼠肝缺血再灌注损伤诱导型一氧化氮合酶表达与肝细胞凋亡的关系

目的观察肝缺血再灌注(I/R)损伤时诱导型一氧化氮合酶(iNOS)在肝组织中的表达及与肝细胞凋亡的关系,探讨其可能的机制。方法选健康雄性Wistar大鼠48只,随机分为假手术组、缺血30min组(I组)、缺血30min即刻再灌注组(I/R组)、缺血30min再灌注后1h组(I/R1h)、缺血30min再灌注后2h组(I/R2h)、缺血30min再灌注后4h组(I/R4h),每组8只。分别测定各组谷丙转氨酶(GTP)、碱性磷酸酶、γ-谷氨酰转肽酶含量及观察肝脏组织HE染色,应用免疫组化法分别测定各组大鼠iNOS在肝组织的表达,应用原位细胞凋亡法测定肝细胞凋亡。结果肝脏I/R过程导致了肝脏明显的损伤,表现为肝血清酶升高(P<0.01),肝细胞水肿,炎性细胞浸润,甚至有细胞坏死。病理组织学变化与GTP变化一致。肝组织iNOS在I/R组即有表达增高(P<0.01),I/R组与I组、I/R1h组与I/R组相比有统计学差异(P<0.05)。细胞凋亡指数I/R组与假手术组比较明显增加(P<0.01),I/R组与I组,I/R2h组与I/R1h组、I/R4h组与I/R2h组相比均有统计学差异(P<0.01)。iNOS与肝细胞凋亡指数间存在显著正相关(r=0.952),P<0.01)。结论肝脏I/R损伤可引起肝组织损伤及肝细胞凋亡,肝细胞的凋亡与iNOS的高表达有关。

Relationship between expression of iNOS and liver cellular apoptosis following liver ischemia/ reperfusion injury in rats

Objective To study the relationship between the expression of inducible nitric oxide synthase (iNOS) and liver cellular apoptosis following liver ischemia/reperfusion(I/R) injury in rats.Methods A model of liver I/R injury was established by imitation.Forty eight male Wistar rats were randomly divided into 6 groups: sham operation,ischemia 30min without reperfusion(group I),reperfusion following ischemia-30min (group I/R).1 hour reperfusion following ischemia 30min(group I/R 1h),2 reperfusion following ischemia 30min (group I/R 2h) and 4 reperfusion following ischemia 30 min (group I/R 4h).The contents of glutamic-pyruvic transaminase (GPT) and alkaline phosphatase (AKP),γ-glutamyl transpeptidase(γ-GT) in the serum were examined,respectively and liver tissue was observed by HE staining.The expression of iNOS in liver tissue were examined by immunohistochemical technique in each group. The changes of hepato- cellular apoptosis were measured by in situ cell apoptosis technique. Results During I/R,the remarkable liver cellular injury can be found,and the liver cellular edema,inflammatory cellular infiltration, even cellular necrosis and matched enzyme in serum increased. The contents of iNOS rose in I group (P<0.01)and reached to the peak in I/R4h group.Apoptosis exponent in group I/R was significantly higher than that in group of sham operation(P<0.01),and the exponent was increasing endlessly following the process of reperfusion injury .And there was a positive corelation between the expression of iNOS and apoptosis exponent (P<0.01,r=0.952).Conclusion Liver I/R injury leads to liver tissues injury as well as liver cellular apoptosis.The development of liver cellular apoptosis is related to the expression of iNOS.