Franz P, Hauser-Kronberger C, Böck P, Quint C, Baumgartner W D
ENT Department, University of Vienna, Austria.
Acta Otolaryngol. 1996 Sep;116(5):726-31. doi: 10.3109/00016489609137914.
Nitric oxide synthase (NOS) isoforms I and III were localized in the guinea pig cochlea by indirect immunohistochemistry using frozen sections and paraffin sections. NOS I staining was observed in the cytoplasm of outer hair cells, in nerve cell somata and fibers of the spiral ganglion, and in axonal profiles of the spiral lamina next to the base of inner hair cells. In addition, lining cells of the inner sulcus and limbus, and cells of the spiral ligament stained for NOS I but vascular walls remained unstained. NOS III reactivity was seen in the cytoplasm of outer and inner hair cell, in lining cells of the limbus, and on the endolymphatic surface of marginal cells. Staining for NOS III of spiral ganglion perikarya showed varying intensity. Endothelial cells of cochlear glomeruli reacted for NOS III. NOS III in vascular endothelial cells implies regulatory effects of nitric oxide (NO) on vascular wall tonus and cochlear blood supply. NOS I in cochlear neurons indicates these cells as possible sources for NO during neuronal activity. Activated neurons may provide NO that adjusts cochlear perfusion to neuronal activity. Finally, NO that is liberated from hair cells or afferent synaptic terminals may act as an inhibitor on N-methyl-D-aspartate (NMDA) receptors (negative feed-back inhibition).
通过使用冰冻切片和石蜡切片的间接免疫组织化学方法，在豚鼠耳蜗中定位了一氧化氮合酶（NOS）同工型I和III。在外侧毛细胞的细胞质、螺旋神经节的神经细胞胞体和纤维以及内侧毛细胞基部旁边的螺旋板层的轴突轮廓中观察到NOS I染色。此外，内沟和边缘的衬里细胞以及螺旋韧带的细胞对NOS I染色，但血管壁未染色。在外侧和内侧毛细胞的细胞质、边缘的衬里细胞以及边缘细胞的内淋巴表面观察到NOS III反应性。螺旋神经节神经元胞体的NOS III染色显示出不同的强度。耳蜗小球的内皮细胞对NOS III有反应。血管内皮细胞中的NOS III意味着一氧化氮（NO）对血管壁张力和耳蜗血液供应具有调节作用。耳蜗神经元中的NOS I表明这些细胞可能是神经元活动期间NO的来源。激活的神经元可能提供NO，以根据神经元活动调节耳蜗灌注。最后，从毛细胞或传入突触末端释放的NO可能作为N-甲基-D-天冬氨酸（NMDA）受体的抑制剂（负反馈抑制）。
