甲状腺激素对脓毒症大鼠肠屏障功能的影响

Effect of thyroid hormone on gut barrier function of septic rats

目的探讨补充甲状腺激素对脓毒症大鼠肠屏障功能的影响。方法将22只雄性SD大鼠随机分成3组:假手术组、脓毒症组、三碘甲状腺原氨酸(T3)干预组。制作盲肠结扎打孔(CLP)的脓毒症模型,应用荧光光谱分析仪检测自肠腔进入门静脉的荧光标记葡聚糖(FITC-D)的浓度,用透射电镜观察黏膜细胞间隙FITC-D颗粒的量。结果CLP后21h,假手术组血游离T3(FT3)、游离甲状腺素(FT4)浓度分别为(3.44±1.40)pmol/L和(9.53±3.39)pmol/L,脓毒症组为(1.59±0.20)pmol/L和(3.41±2.14)pmol/L,明显低于假手术组(P<0.05),干预组FT3浓度为(3.40±1.65)pmol/L,明显高于脓毒症组(P<0.05)。假手术组门静脉FITC-D浓度(0.84±0.15)μg/ml,脓毒症组为(1.73±0.39)μg/ml,高于假手术组(P<0.01),T3干预组(1.16±0.26)μg/ml,明显低于脓毒症组(P<0.01)。电镜显示T3干预后的肠黏膜细胞间隙及毛细血管的FITC-D颗粒明显减少。结论外源性甲状腺激素可降低大鼠肠黏膜的通透性,对脓毒症时肠黏膜屏障功能具有保护作用。

Objective To investigate the effect of exogenous thyroid hormone on gut barrier fun ction of septic rats.Methods 22male SD rats were divided into thre e groups:sham laparotomy (S),cecal ligation and puncture(CLP),and CLP plus T 3 .Septic rat model was established th rough CLP method.Fluorescence spectrometry was used to measure the concentration of FITC-dextran from lumen to portal veins.Quantity of FITC-dextran in cellula r gaps of intestinal mucosa was observed under transmission eletron microscopy(TEM).Results21hours after CLP,serum free T 3 or T 4 concentration in CLP group was lower than that in S group respectivelyCLP(1.59±0.20)pmol /L?(3.41±2.14)pmol /L vs S (3.44±1.40)pmol /L?(9.53±3.39)pmol /L;P<0.05Serum free T 3 concentration in CLP plus T 3 group was elevated significantly(3.40±1.65)pmol /L,P<0.0Portal veins concentration of FITC-dextran in CLP group was higher than that in S groupCLP(1.73±0.39)μg /L vs S (0.84±0.15)μg /L;P<0.01,and in CLP plus T 3 group(1.16±0.26)μg /L,P<0.01.A significant diminution of g ranular FITC-dextran in cellular gaps and capillary of intestinal mucosa was observed in CLP plus T 3 group as compared to CLP group.Conclusion Exogenous thyroid hormone can decre ase gut permeability in rats,and pro tect gut barrier function in sepsis.