大鼠肠缺血再灌注时肺组织β-防御素-2 mRNA表达的变化

目的 观察大鼠肠缺血再灌注时肺组织β-防御素-2(BD-2)mRNA表达的变化.方法 72只雄性SD大鼠随机分为2组(n=36):假手术组(S组)和肠缺血再灌注组(II/R组).采用夹闭肠系膜上动脉(SMA)的方法制备肠缺血再灌注模型.II/R组阻断SMA 1 h后再灌注,S组仅分离SMA.分别于再灌注即刻(T0),再灌注15(T1)、30(T2)、60 min(T3)、3 h(T4)和6 h(T5)时处死6只大鼠,取肺组织,光镜下观察肺组织病理学结果,计算肺通透性指数(PPI),检测肺组织肿瘤坏死因子-α(TNF-α)含量和BD-2 mRNA表达水平.结果 S组肺组织结构未见异常,II/R组出现肺水肿和中性粒细胞浸润.与S组比较,II/R组再灌注各时点PPI升高,BD-2 mRNA表达上调,T0-3时TNF-a含量升高(P＜0.05或0.01).II/R组BD-2 mRNA表达水平与TNF-a含量及PPI的相关系数分别为0.823和-0.615(P＜0.01).结论 大鼠肠缺血再灌注时肺组织BD-2基因表达上调.

Changes in β-defensin-2 mRNA expression in the lung tissue after intestinal ischemin-reperfusion in rats

Objective To investigate the effects of intestinal ischemia-reperfusion(II/R)on the p-defensin-2 mRNA expression in the lung tissue in rats.Methods Seventy-two male SD rats weighing 250-300 g were randomly allocated to one of 2 groups(n=36 each):group Ⅰ sham operation(S)and group Ⅱ II/R.Intestinal I/R was produced by occlusion of superior mesenteric artery(SMA)for 60 min followed by reperfusion.Six animals were killed at each of the following time points:the onset of reperfusion(T0),15,30,60 min (T1,2,3)and 3,6 h(T4,5)of reperfusion in each group.Lung tissue specimens and broncho-alveolar lav~e fluid (BALF)were obtained for microscopic examination and determination of pulmonary permeability index(PPI),TNF-α content and BD-2 mRNA expression(by RT-PCR).ResultsMicroscopic examination showed edema and PMN infiltration in the lung in group II/R.The PPI and BD-2 mRNA expression were significantly higher in group II/R than in group S.The TNF-α content was significantly higher at T0-3 in group II/R than in group S(P＜0.05or 0.01).The BD-2 mRNA expression was positively correlated to the TNF-α content(r=0.823,P＜0.01)and negatively correlated to PPI(r=-0.615,P＜0.05).Conclusion BD-2 gene expression in the lung tissue is up-regulated after intestinal I/R in rats.