기니픽의 정상 내이에서의 NOS의 분포 양상

Abstract

Background and Objectives：The purpose of this study is to find out the exact distribution of nitric oxide synthase (NOS) in the cochlea and vestibular organ of normal guinea pig. Nitric oxide (NO) is synthesized from L-arginine catalyzed by NOS and neurotransmision of the inner ear and the regulation of cochlear blood flow in physiological condition. In addition, exces NO is involved in cytotoxicity. Materials and Method：Five normal guinea pigs were used. Antibodies to thre isoforms of NOS (nNOS, eNOS, iNOS) were utilized to stain the parafin sections of cochlea and vestibular organ (crista and maculae utriculi). Staining patterns were compared to previous reports. Results：Neuronal NOS (nNOS) was constitutively expressed in the lateral cochlear wall (stria vascularis, spiral ligament), spiral ganglion, hair cells and supporting cells in the cochlea. In the vestibular organs, hair cels were well expressed. Endothelial NOS (eNOS) was expresed in the vascular endothelium, cochlear lateral wall, basal parts of hair cells and spiral ganglion in the cochlea. Vascular endothelium and nerve fiber including nerve calyx were also prominently expressed. No inducible NOS (iNOS) was identified in any sections. Conclusion：Neuronal and endothelial NOS were constitutively expresed in the inner ear of normal guinea pig. This distribution can explain the role of (Korean J Otolaryngol 2003 ;46 :627-33)