Expression of inducible nitric oxide synthase in rat junctional epithelial cells

结合上皮（JE）比口腔沟上皮（OSE）和口腔上皮（OE）更早受到引起牙周炎症的刺激的影响。一氧化氮（NO）具有多种生物活性，并被认为可调节炎症。NO是由L-精氨酸通过一氧化氮合酶（NOS）产生的，分为神经型NOS（nNOS）、内皮型NOS（eNOS）和诱导型NOS（iNOS）。转录因子NF-κ B B在诱导型一氧化氮合酶基因的转录调控中起重要作用。在这项研究中，我们研究了免疫组织化学表达的诱导型一氧化氮合酶和eNOS和NF-κ B在大鼠牙龈。iNOS、eNOS和NF-κ B B的免疫反应产物分布于牙龈的各种细胞（JE细胞、OSE细胞、OE细胞、成纤维细胞和内皮细胞）。在牙龈中，SP应用后30分钟，在10-4 M的浓度，SP对表达的iNOS在JE细胞的影响，没有检测到免疫化学。这表明，JE细胞可能产生NO，并形成对有害刺激如细菌的防线。NO在JE细胞中的作用有待进一步研究。

The junctional epithelium (JE) is affected earlier than oral sulcular epithelium (OSE) and oral epithelium (OE) by stimuli that evoke periodontal inflammation. Nitric oxide (NO) has a variety of biological activities and is thought to modulate inflammation. NO is generated from L-arginine by NO synthases (NOS), classified into neural-type NOS (nNOS), endothelial-type (eNOS) and inducible-type (iNOS). The transcription factor NF-kappa B plays a critical role in the transcriptional regulation of iNOS gene. In this study we investigated the immunohistochemical expression of iNOS and eNOS and NF-kappa B in rat gingiva. And we also investigated the effect of neuropeptide substance P (SP) on expression of iNOS in JE cells.The immunoreactive products of iNOS, eNOS and NF-kappa B were found throughout various cells (JE cells, OSE cells, OE cells, fibroblasts and endothelial cells) in the gingiva. In the gingiva, 30 min after SP application at concentrations of 10-4 M, the effect of SP on expression of iNOS in JE cells was not detected immunohistochemically. It was suggested that JE cells might produce NO and form a line of defense against harmful stimuli such as bacteria. Further studies are needed to determine the role of NO in JE cells.