Chakder S, Bandyopadhyay A, Rattan S
Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Am J Physiol. 1997 Dec;273(6):C1868-75. doi: 10.1152/ajpcell.1997.273.6.C1868.
Nitric oxide synthase (NOS) has been characterized in different tissues, and its localization has been suggested in different neuronal tissues, including the myenteric neurons and other nonneuronal cells. The present study examined the distribution of the neuronal NOS (nNOS) mRNA in different tissues of the opossum gastrointestinal tract, internal anal sphincter (IAS) smooth muscle cells, and myenteric neurons using slot-blot and Northern blot hybridization techniques with a specific rat brain nNOS cDNA probe. Significant levels of nNOS gene expression were found in both smooth muscle cells and myenteric neurons of the opossum IAS. This finding was confirmed by reverse transcriptase-polymerase chain reaction analysis of the RNA obtained from cultured opossum IAS smooth muscle cells and myenteric neurons and also from human intestinal smooth muscle and neuroblastoma cell lines. Pyloric sphincter had the highest level of nNOS gene expression compared with other gastrointestinal tissues. There was no significant difference in the nNOS gene expression between other sphincteric and nonsphincteric tissues examined. The present study shows the presence of nNOS gene expression in both neurons and smooth muscle cells. The higher levels of nNOS gene expression in the pyloric sphincter compared with other tissues may have pathophysiological significance in some disease conditions.
一氧化氮合酶（NOS）已在不同组织中得到表征，并且其在不同神经组织中的定位也已得到提示，包括肌间神经元和其他非神经细胞。本研究使用特异性大鼠脑nNOS cDNA探针，通过狭缝印迹和Northern印迹杂交技术，检测了负鼠胃肠道不同组织、肛门内括约肌（IAS）平滑肌细胞和肌间神经元中神经元型NOS（nNOS）mRNA的分布。在负鼠IAS的平滑肌细胞和肌间神经元中均发现了显著水平的nNOS基因表达。从培养的负鼠IAS平滑肌细胞和肌间神经元以及人肠道平滑肌和神经母细胞瘤细胞系获得的RNA进行逆转录-聚合酶链反应分析，证实了这一发现。与其他胃肠道组织相比，幽门括约肌的nNOS基因表达水平最高。在所检查的其他括约肌和非括约肌组织之间，nNOS基因表达没有显著差异。本研究表明神经元和平滑肌细胞中均存在nNOS基因表达。与其他组织相比，幽门括约肌中nNOS基因表达水平较高可能在某些疾病状态下具有病理生理学意义。
