【摘要】 目的:研究哮喘大鼠模型肺组织中COX-1和COX-2mRNA表达随致敏时间变化的关系以及糖皮质激素对COX-1和COX-2mRNA表达的影响。方法:将90只成年雌性SD大鼠分为卵清蛋白致敏组,激素预处理卵清蛋白致敏组和生理盐水对照组,最后一次卵清蛋白激发后分别于1、3、6、24、48h处死,测量各时段肺组织中COX-1和COX-2mRNA含量。结果:3组大鼠COX-1mRNA表达均不随时间变化,组与组之间表达差异无显著性;卵清蛋白致敏组COX-2mRNA于激发后1h较对照组升高[(56.23±6.78%)%vs(13.65±8.33)%,P<0.05)犦,3h达到高峰[(110.26±13.34)%,P<0.05)犦,以后迅速降到基础水平;激素预处理卵清蛋白激发组和生理盐水对照组COX-2mRNA表达不随时间变化,表达水平无明显差异。结论:在卵清蛋白致敏的哮喘大鼠模型肺组织中COX-2mRNA表达一过性上调,且这种上调可被糖皮质激素所抑制。COX-2可能在哮喘的发病机制中起到了关键作用。更多还原

【Abstract】 Objectives To investigate the expression of COX-1 and COX-2 mRNA during allergic inflammation in rat lungs and its relation with challenge time. The effect of corticosteroid on the production of COX-1 and COX-2 mRNA was also investigated. Methods Ninety female SD rats were divided into the study group and the control group. In the study group, rats were subdivided into two groups. One group received pre-treatment with intraperitoneal injection with corticosteroid (10 mg/kg),and another group did not receive pre-treatmented corticosteroid. Rats were sensitized and challenged by ovalbumin(OVA),and put to death at 1 h、3 h、6 h、24 h and 48 h after OVA challenge. Lung tissue samples were obtained for analysis of COX-1 and COX-2 mRNA levels. Results The COX-1 mRNA expression did not correlate with challenge time and was seen no difference in all groups. The ovalbumin-sensitized animals showed a robust induction of COX-2 mRNA expression at 1h[(56.23±6.78) vs (13.65±8.33),P< 0.05], after ovalbumin challenge and reached its top level at 3h, whereas the rats which received pre-preatmented corticosteroid remained unchanged. Conclusions Upregulation of the COX-2 mRNA level during allergic inflammation in the lungs can be inhibited by corticosteroid. Thus COX-2 may play a crucial role in the airway pathophysiology of asthma.更多还原