哮喘大鼠肺与大脑皮层的白三烯B_4含量和白三烯A_4水解酶的mRNA表达上升

Increase of LTB_4 level and expression of LTA_4-hydrolase mRNA in lung tissue and cerebral cortex in asthmatic rats

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 m RNA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 m RNA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 L TA4水解酶 m RNA的表达也明显提高。地塞米松 (DXM,0 .5 mg/ kg,ip)可以减少 L TB4含量的增加 ,抑制 LTA4水解酶 m RNA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 m R-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。

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.