Clucocorticoid receptor expression in the lung tissue in endotoxic shock rat

Abstract

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. Key words: Ghcocorticoid; GR mRNA; Vasoactive intestinal peptide; LPS; Shock; Inflammation; Lung injury; Rat