摘要
目的动态观察内毒素(LPS)所致急性肺损伤(acutelunginjury,ALI)大鼠肺组织内趋化因子Fractalkine(FKN)的表达变化,及糖皮质激素对其的影响。方法将42只大鼠随机分为空白对照组、模型组(LPS)及地塞米松干预组(DEX),其中LPS组和DEX组再分为1h、2h、4h3个时相组,每组6只,LPS组和DEX组大鼠经尾静脉注射LPS(4mg/kg)建立ALI大鼠模型。采用ELISA、RT-PCR等方法,观察ALI大鼠模型肺组织病理学改变、肺湿干重比值(W/D)及血清TNF-α变化,并检测肺组织FKNmRNA的表达,同时观察地塞米松对上述指标的影响。结果模型组1h、2h与4h3个时相组肺损伤病理改变、肺W/D、血浆TNF-α均明显增高,地塞米松能减轻ALI大鼠肺组织炎症反应、肺W/D值及血清TNF-α水平(P均<0.05)。正常大鼠肺组织FKNmRNA有表达,模型组3个时相亚组肺组织FKNmRNA表达较正常组明显增加(P<0.05),在2h时点达峰值,地塞米松能下调ALI大鼠肺组织FKNmRNA表达(P<0.05)。FKNmRNA的表达量与血清TNF-α水平呈正相关(r=0.674,P<0.05)。结论早期应用地塞米松可降低TNF-α水平,下调肺组织FKNmRNA的表达,这可能是糖皮质激素对内毒素致急性肺损伤实验大鼠保护作用机制之一。
Objective To investigate the effect of dexamethasone on the expression of fractalkine （FKN） in lipopolysaccharide （LPS）-induced acute lung injury（ALl）. Methods The rat model of ALI was established by injection of LPS at the dose of 4 mg/kg. 42 Wistar rats were randomly divided into the normal group （n=6）, LPS group （n=18）, and dexamethasone （DEX） group （n=18）, and then the rats in both LPS and DEX groups were divided into three subgroups （1 h, 2 h and 4 h after injection of LPS）, respectively. The pathological condition and the wet/dry ratio （W/D） of the lung were observed, and serum TNF-α level, and FKN mRNA of the lung were detected with ELISA and RT-PCR. Results The W/D, serum TNF-α level, and FKN mRNA of the lung were significantly increased in LPS group, compared with those in normal group （all P〈0. 05）, but the W/D, serum TNF-α level, and FKN mRNA of the lung in the DEX group were much more decreased than those in the LPS group （all P〈0.05）. In addition, the expression of FKN mRNA in the lung tissue positively correlated with the concentration of TNF-α （r = 0. 674, P〈 0. 05）. Conclusion The findings suggested that pre-treatment with dexamethasone could inhibit the TNF-α level and prevent the increase of the expression of FKN mRNA, which may be one of the mechanisms by which DEX serves as a protection against LPS-induced lung injury.
出处
《四川大学学报（医学版）》
CAS
CSCD
北大核心
2006年第2期250-253,共4页
Journal of Sichuan University(Medical Sciences)
