内毒素性休克大鼠肺组织糖皮质激素受体mRNA的表达

目的 探讨内毒素(LPS)性休克大鼠肺组织糖皮质激素受体(GR)mRNA的表达.方法 56只SD大鼠,随机(随机数字法)分IPS休克组(16只)、LPS+血管活性肠肽(vasosctive intestinal peptide,VIP)组(16只)、LPS+VIP+糖皮质激素(GC)组(16只)和对照组(8只).尾静脉注射LPS制作休克模型,尾静脉注射LPS 10 mg/kg后,分别于15 min内注射VIP 5 nmol/kg或VIP 5 nmol/ks+甲基强的松龙3 mg/kg,对照组注射等容量生理盐水,分别于沣射后6 h和24 h处死,留取肺标本,观察肺组织病理变化,RT-PCR榆测肺组织GR mRNA的表达.结果 (1)肺组织病理改变:LPS组见肺泡腔结构破坏、肺泡间隔增宽、炎性细胞浸润、出血、间质水肿,细胞器破坏,LPS+VIP组和IPS+VIP+GC组病变较轻.(2)GR mRNA的表达:注射LPS后6 h,LPS组和LPs+VIP组GR mRNA表达下降,与对照组相比,差异具有统计学意义(P＜0.05).LPS组下降较LPS+VIP组稍明显,但差异无统计学意义(P＞0.05).24 h GR mRNA表达恢复.LPS+VIP+GC组GR mRNA表达6 h增加,24 h GR mRNA表达更高(P＜0.05).结论 LPS致肺损伤时,肺组织GR mRNA的表达减少.VIP和GC可抵抗炎症反应、减轻肺损伤,其机制可能与增强GR mRNA的表达有关.

Clucocorticoid receptor expression in the lung tissue in endotoxic shock rat

Objective To investigate the effects of vasoactive intestinal peptide(VIP)on TLR 2,4 mRNA expressions in the lung tissue in endotoxic shock rat induced by LPS rat.Method Fifty six SD rats were far.rely (random number)divided into 4 groups,including LPS shock group(n=16),LPS+VIP group(n=16),LPS+V1P+GC group(n=16),and control group(n=8).LPS shock model was made by intravenously injecting with LPS(10 mg/kg);rats in the LPS+VIP group were intravenously injected with VIP after LPS;rats in the LPS+VIP+GC group were injected with VIP and methylprednisolone together with LPS;rats in the control group were given with normal saune.The rats were sacrificed at 6 h,24 h after injected.The lung tissues were collected.Pathological changes of the lungs were observed under hght microscope and electron microscope.The GR mRNA expressions were assessed by RT-PCR in the lung tissues.Results(1)Lung histopathology:necrotic abscission cells increased in alveolar space,inflammatory cells infiltration and lung interstitial edema appeared in LPS shock group.However,pathological changes in LPS+VIP group and LPS+VIP+GC group were milder than those in LPS shock group.(2)After 6 hours LPS injection,the GR mRNA expression in LPS group and LPS+VIP group were significantly lower as compared with those of the control group(P＜0.05),the GR mRNA expressions of LPS+VIP+GC group at 6 h and 24 h were significantly higher than those of the other groups(P＜0.05).Condusions Expression of GR mRNA decreases in rats with LPS-induced lung injury.VIP+GC can reduce lung injury,which may have correlation with up-regulation of GR mRNA expression.