一氧化氮合酶基因在先天性巨结肠中的表达

Nitric Oxide Synthase gene Expression in Different Colonic Segments of Hirschsprung's Disease

目的 研究神经型一氧化氮合酶 (n NOS)基因在先天性巨结肠 (HD)不同肠段的表达。方法 分别取 8例先天性巨结肠患者病变段和正常段平滑肌组织 ,经处理后提取总 RNA,应用逆转录多聚酶链反应 (RT- PCR)扩增目的基因和看家基因片段 ,观察病变段和正常段的 n NOS基因的表达 ,并与看家基因 (GAPDH)在病变段和正常段的表达作对比。结果 8例患者正常段 n NOS和 GAPDH均有明显的表达 ,病变段 GAPDH亦有明显的表达而 n NOS均无表达。结论 先天性巨结肠患者病变段抑制性神经递质一氧化氮 (NO)减少的原因可能是 n NOS的 m RNA的减少或缺如 。

Objective To investigate the changes of neuronal nitric oxise synthase (nNOS) mRNA expression in different segments of rectum in patients with Hirschsprung's disease (HD). Methods Smoooth muscle tissues from diseased and normal segments of 8 patients with HD were isolated respectively and preserved in -70 ℃ refrigerator. RNA of each segment was isolated, then the DNA segments of nNOS and a house keeper gene (glyceraldehydes 3 phosphate dehydrogenase, GAPDH) were amplified using reverse transcription polymerase chain reaction (RT PCR) technique. Results With 30 cycles of PCR reaction, significant expression of nNOS were observed in the normal segments in all 8 patients, whereas in the diseased segments in all 8 patients, no expression of nNOS mRNA was detectable. Conclusion The cause of the lack of inhibitory neurotransmitter NO which results in achalasia of the diseased segments is the lack of expression of nNOS mRNA rather than the defect of translation or nNOS itself.