异型一氧化氮合酶在爪蛙鼻粘膜中的分布

用还原型辅酶Ⅱ黄递酶组织化学和一氧化氮合酶（ＮＯＳ）免疫细胞化学技术研究了成年爪蛙（Ｘｅｎｏｐｕｓｌａｅｖｉｓ）鼻粘膜ＮＯＳ的阳性结构。嗅上皮中嗅感觉神经元和支持细胞，以及固有层中的神经束、血管和粘膜下腺均呈还原型辅酶Ⅱ黄递酶阳性染色。在嗅上皮中，未见Ⅰ型或Ⅱ型ＮＯＳ抗体免疫反应阳性结构，但鼻内侧窦和内侧窦口顶嗅上皮中的嗅感觉神经元见有Ⅲ型ＮＯＳ强免疫反应。在固有层中，Ⅰ型或Ⅲ型ＮＯＳ免疫反应性存在于神经束和血管中，未见于粘膜下腺的腺泡中。结果表明，不同异型的ＮＯＳ存在于爪蛙鼻粘膜中，提示一氧化氮可能参与爪蛙的化学感觉活动。

DISTRIBUTION OF ISOFORMS OF NITRIC OXIDE SYNTHASE IN THE NASAL MUCOSA OF XENOPUS LAEVIS *

NADPH diaphorase histochemistry and nitric oxide synthase (NOS) immunocytochemistry were used to localize putative NOS positive structures in the nasal mucosa of adult Xenopus laevis. Olfactory receptor neurons and supporting cells in the olfactory epithelium, together with nerve bundles, blood vessels and submucosal glands in the lamina propria, were NADPH diaphorase positively stained. Isoform specific antibodies to NOS I and NOS II did not stain cells in the epithelium, but strong immunoreactivity to NOS III appeared in the olfactory receptor neurons in the olfactory epithelium of medial diverticulum and oral cupola of medial diverticulum. In the lamina propria, NOS I or NOS III immunoreactivity was found in nerve bundles and blood vessels, but not in acini of submucosal glands. Our findings revealed that isoforms of NOS were present in Xenopus nasal mucosa, suggesting that NO might participate in the chemosensory activities of Xenopus laevis.