甲状腺激素对脓毒症大鼠血清一氧化氮浓度及肠粘膜一氧化氮合酶的影响

Effect of thyroid hormone on serum NO concentration and iNOS activity of intestinal mucosa in septic rats

目的探讨补充外源性甲状腺激素对脓毒症大鼠血清一氧化氮 (NO)及肠粘膜诱导型一氧化氮合酶 (iNOS)的影响。方法应用盲肠结扎打孔法制作大鼠脓毒症模型 ,32只雄性SD大鼠随机分为 4组 :假手术组、脓毒症组、T3预防组及T3治疗组。术后 2 4h检测血清NO及甲状腺激素浓度 ,取末端回肠HE染色以判断组织损伤程度 ,同时应用免疫组化检测小肠粘膜中iNOS的表达。结果T3预防组动物死亡率较脓毒症组低 (LogRank检验值 =3 85 ,P <0 0 5 ) ,血清NO浓度降低 (F =19 6 ,P <0 0 1) ,肠粘膜损伤程度减轻 (χ2 =5 30 3,P <0 0 5 ) ,肠粘膜上皮细胞iNOS的表达明显下降(χ2 =4 876 ,P <0 0 5 )。结论脓毒症时补充外源性甲状腺激素对肠粘膜屏障具有明显的保护作用。

Objective This study was to investigate the effect of exogenous thyroid hormone on serum NO and iNOS activity of intestinal mucosa in septic rats. Methods Septic model was established by cecal ligation puncture(CLP) in male SD rats. Triiodothyronine(T 3) was administered intraperitoneally to correct the low T 3 syndrome of septic rats. Blood was collected to examine serum NO and thyroid hormone concentration. Intestinal mucosa iNOS activity was assayed using immunochemical stain. Results Mortality rate in the prevention group was significantly lower than the septic group(Log rank=3.85, P<0.05). Serum NO concentration was significantly lower in the prevention group(F=19.6,P<0.01). The degree of inflammatory injury of intestinal mucosa was much milder in the prevention group than in the the septic group(χ 2=5.303, P<0.05). Mucosa iNOS activity was also significantly lower in the prevention group(χ 2=4.876, P<0.01). Conclusion Thyroid hormone protects the intestinal mucosa barrier inhibiting the expression of iNOS.