体外循环术中白细胞滤过技术对幼犬心肌组织 cNOS和iNOS表达的影响

目的通过检测未成熟心肌组织中结构型及诱导型一氧化氮合酶(cNOS和iNOS)的表达,及用RT-PCR法观察cNOSmRNA的异常基因表达,从分子水平上探讨在体外循环(CPB)中应用白细滤过技术对幼犬心肌组织的影响。方法将12只杂种幼犬随机分为两组:白细胞滤过组(LD-CPB组和对照组(NO-LD组)。针对幼犬建立CPB模型,仅在LD-CPB组的动脉通路中加上白细胞滤过器。主脉开放30min,测定静脉血中NO浓度;术毕测心肌组织中一氧化氮同功酶的活性,并用RT-PCR法观cNOSmRNA的基因表达。结果再灌注30min后,LD-CPB组的血清NO浓度明显高于NO-LD组(P0.0001)。术毕LD-CPB组的心肌NOS活性和cNOS活性均明显高于NO-LD组(P<0.001,P<0.001),iNOS的活性两组间无显著性差异(P=0.39)。LD-CPB组心肌组织cNOSmRNA基因表达较NO-LD组调(P<0.05)。结论在体外循环手术中应用白细胞滤过技术可以上调cNOSmRNA的基因表达,保cNOS在未成熟心肌血管内皮细胞的高表达,相对提高由cNOS催化分泌的NO的浓度,从而减轻CPB成的因中性粒细胞激活而对未成熟心肌组织的炎症反应,达到保护未成熟心肌的作用。

The Expression of cNOS and iNOS in the Neonate Canine Myocardium During Cardiopulmonary Bypass: Influence of the Leukocyte Depleted Filter

Objective To detect the expression of cNOS and iNOS,and the abnormal gene of cNOS mRNA in immature myocardium during CPB using RT -PCR technique,to evaluate the influence of leukocyte depleted(LD)filter on the immature myocardium during the CPB.Methods In a randomized,prospective study,12neonate canine were randomly divided into two groups:LD-CPB group(n=6)and control(NO-LD)group(n=6).Myocardial tissue of left ventricle was obtained at the end of CPB.The activities of cNOS,iNOS and expression of cNOS mRNA gene in the immature myocardium were detected by using RT-PCR method.Results Serum NO content in LD-CPB group was obviously higher than those of NO-LD group following30min reperfusion.NOS and cNOS values in LD-CPB group were increased significantly than that of NO-LD group after the operation(P<0.001,P<0.001).However,there was no significantly difference between the two groups in iNOS values(P<0.39).As compared with NO-LD group,up-regulation degree of the expression of cNOS mRNA myocardium,nitric oxide synthase were significantly high in LD-CPB group(P<0.05).Conclusion s Using the leukocyte depleted filter during the CPB can up-regulate the expression of the abnormal gene cNOS mRNA,can keep the high expression of cNOS in the vascular endothelial cell s of the immature myocardium,and increase the concentration of NO catalysed by cNOS relatively.Thus the inflammatory reaction of mycoardial tissue induced by activate d neutrophils could be decreased during the CPB,and then protecting the immature myocardium.