哮喘大鼠肺与大脑皮层的白三烯B4含量和白三烯A4水解酶的mRNA表达上升

目的：观察抗原攻击的哮喘大鼠肺组织和大脑皮层的LTB4含量及其合成酶mRNA表达量的变化。方法：用卵白蛋白致敏大鼠，抗原攻击后，用反向高效液相法(RP—HPLC)测定肺组织和大脑皮层匀浆的LTB4含量。用半定量RT—PCR法检测LTA4水解酶mRNA的表达量。结果：哮喘大鼠肺组织和大脑皮层匀浆中的LTB4含量显著高于正常对照组，其LTA4水解酶mRNA的表达也明显提高。地塞米松(DXM，0．5mg／kg，ip)可以减少LTB4含量的增加，抑制LTA4水解酶mRNA的表达。结论：哮喘大鼠肺组织和大脑皮层的LTB4含量及其合成酶的mR—NA的表达同步增高，提示哮喘时中枢神经系统对肺组织可能有神经免疫调节作用。

Increase of LTB4 level and expression of LTA4-hydrolase mRNA in lung tissue and cerebral cortex in asthmatic rats

Objective: To investigate antigen-induced changes of leukotriene B 4(LTB 4)content and LTA 4-hydrolase mRNA expression in lung tissue and cerebral cortex in sensitized rats. Methods: The contents of LTB 4 in lung tissue and cerebral cortex homogenates and LTA 4-hydrolase mRNA expression after antigen challenge by aerosol were respectively detected by reverse-phase high performance liquid chromatography(RP-HPLC) and semi-quantitative RT-PCR. Results: The LTB 4 levels in lung tissue and cerebral cortex homogenates in asthmatic rats were significantly higher than those in control(P<0.05),and LTA 4-hydrolase mRNA expression was also increased in asthmatic group. Dexamethason(DXM,0.5 mg/kg,ip) decreased the LTB 4 content and inhibited the LTA 4-hydrolase mRNA expression significantly in asthmatic rats(P<0.05). Conclusion: LTB 4 content and LTA 4-hydrolase mRNA expression in cerebral cortex and lung tissue are increased in asthmatic rats,and there may exist neuroimmunological cross-talking between central nervous system and lung tissue in asthma.