小鼠感染日本血吸虫后iNOS的表达及NO介导的杀虫作用研究

The iNOS expression induced by schistosomula of Schistosoma japonicum and the larvicidal activity mediated by NO in mice

目的研究小鼠在感染日本血吸虫后肺部诱导型一氧化氮合酶(iNOS)的动态表达及一氧化氮(NO)对童虫的杀伤作用。方法在感染日本血吸虫后不同时间点剖杀小鼠并取其肺组织,用半定量RTPCR的方法检测肺部iNOS的转录水平;用NOS的抑制剂AG(Aminoguanidine,氨基胍)处理感染小鼠,比较处理组与对照组虫荷的高低以确定NO对童虫的杀伤作用。结果未感染小鼠肺部无iNOS转录表达,感染后第4d肺部iNOS有较高水平的转录表达,第9d表达消失;AG处理小鼠的虫荷较未处理组高(P<0.05)。结论移行到肺部的童虫能诱导肺组织表达iNOS,由iNOS产生的NO能对童虫发挥杀灭作用。

To detect the expression of inducible nitric oxide synthase (iNOS) in the lungs of mice infected by Schistosoma japonicum, and to investigate whether this iNOS expression can mediate the larvicidal activity. Mice were euthanatized at day 0, day 4, day 9 p.i. And the RNA was extracted RT-PCR was performed to detect the levels of iNOS mRNA. To confirm whether NO can affect worm burden of infected mice, infected mice were treated with Aminoguanindine-an iNOS inhibitor and worm burdens in inhibited group were compared with the control group. It was found that there was no expression of iNOS in the lungs before challenging,and iNOS expression increased significantly at day 4 p.i, then disappearod at day 9 p.i. Worm burden was significantly higher in the group treated with inhibitor (P<0.05). It condudes that schistosomula migrating to the lungs of mice can induce iNOS expression in the lungs. And NO generated by iNOS can mediate larvicidal activity to the parasites.