Kikuchi Ryuta, Ambe Kimiharu, Kon Hideki, Takada Satoshi, Watanabe Hiroki
Department of Oral and Maxillofacial Surgery, Ohu University, Graduate School of Dentistry.
Division of Oral Histology, Department of Morphological Biology, Ohu University School of Dentistry.
Bull Tokyo Dent Coll. 2018;59(1):15-25. doi: 10.2209/tdcpublication.2017-0007.
Localization of the nitric oxide (NO)-producing enzyme, nitric oxide synthase (NOS), and its functions are currently being investigated in several tissues and organs. It has been suggested that NO is involved in nerve cell death and the development of neurodegenerative disease. The purpose of this study was to immunohistochemically investigate expression of NOS to clarify its function in the degeneration and regeneration of transected mouse sciatic nerve. Scattered neuronal NOS (nNOS)-positive Schwann cells observed on the central side of the stump on day 1 after transection showed an increase in number on day 7. None were observed at the stump on day 14, however. Expression of nNOS was observed in axons extending from the stump. The number of nNOS-positive axons increased on day 21. Inducible NOS was expressed in inflammatory cells at the stump on day 1. This positive reaction subsequently weakened by day 7, however. Endothelial NOS was expressed in blood vessels at the stump on day 7, but decreased thereafter. The results of the present study suggest that NO is involved in the proliferation and migration of Schwann cells, as well as in axon regeneration at an early stage following nerve transection.
目前正在对几种组织和器官中产生一氧化氮（NO）的酶——一氧化氮合酶（NOS）的定位及其功能进行研究。有人提出，NO与神经细胞死亡和神经退行性疾病的发展有关。本研究的目的是通过免疫组织化学方法研究NOS的表达，以阐明其在横断小鼠坐骨神经的变性和再生中的作用。横断后第1天，在残端中央侧观察到散在的神经元型NOS（nNOS）阳性雪旺细胞，第7天其数量增加。然而，在第14天残端未观察到nNOS阳性雪旺细胞。在从残端延伸的轴突中观察到nNOS的表达。nNOS阳性轴突的数量在第21天增加。诱导型NOS在第1天在残端的炎性细胞中表达。然而，这种阳性反应在第7天随后减弱。内皮型NOS在第7天在残端的血管中表达，但此后减少。本研究结果表明，NO参与雪旺细胞的增殖和迁移，以及神经横断后早期的轴突再生。
