Kusafuka T, Puri P
Children's Research Centre, Our Lady's Hospital for Sick Children, Crumlin, Dublin 12, Ireland.
Pediatr Surg Int. 1997;12(8):576-9. doi: 10.1007/BF01371902.
Nitric oxide (NO) has been described as a mediator of smooth muscle relaxation in the mammalian gastrointestinal tract. The enzyme neuronal nitric oxide synthase (NOS) catalyzes the formation of NO. We examined the expression of the neuronal NOS gene at the messenger RNA (mRNA) level in pyloric smooth-muscle biopsy specimens from six patients with infantile hypertrophic pyloric stenosis (IHPS) using a reverse transcription-polymerase chain reaction (RT-PCR) technique. For controls, smooth-muscle layer specimens of pylorus (n=3), ileum (n=2), and colon (n=2) were used. With 31 cycles of PCR reaction, control specimens revealed detectable signals for neuronal NOS mRNA. In contrast, signals of IHPS specimens were undetectable in five cases and very weak in one. By increasing the PCR to 37 cycles, detectable signals for neuronal NOS mRNA were observed in all IHPS specimens, but they were significantly weaker than those of controls. Since a low level of neuronal NOS mRNA may lead to impaired production of NO, our observations indicate that the excessively contracted, hypertrophied pyloric muscle in IHPS is a result of reduced expression of the neuronal NOS gene at the mRNA level.
一氧化氮（NO）被认为是哺乳动物胃肠道平滑肌舒张的介质。神经元型一氧化氮合酶（NOS）催化NO的生成。我们使用逆转录-聚合酶链反应（RT-PCR）技术，检测了6例婴儿肥厚性幽门狭窄（IHPS）患者幽门平滑肌活检标本中神经元型NOS基因在信使核糖核酸（mRNA）水平的表达。作为对照，使用了幽门（n=3）、回肠（n=2）和结肠（n=2）的平滑肌层标本。经过31个循环的PCR反应，对照标本显示出可检测到的神经元型NOS mRNA信号。相比之下，5例IHPS标本的信号无法检测到，1例非常微弱。通过将PCR增加到37个循环，在所有IHPS标本中都观察到了可检测到的神经元型NOS mRNA信号，但它们明显弱于对照标本。由于神经元型NOS mRNA水平较低可能导致NO生成受损，我们的观察结果表明，IHPS中过度收缩、肥厚的幽门肌是神经元型NOS基因在mRNA水平表达降低的结果。
