[Immunohistochemical study of proteoglycans and collagens in the mouse cochlear duct]

Immunohistochemical studies of proteoglycans and collagens (type I and type IV) in the cochlear duct, and of the effects of cisplatin (CDDP), were performed. In cells of the organ of Corti and in the middle layer of the stria vascularis, heparan sulfate proteoglycan (HSPG) and collagens (type I and IV) or collagen-like substances were found. HSPG in these locations appeared to play important roles in the production of auditory sense. The tectorial membrane contained HSPG and collagens (type I and IV). However, no data supporting the concept that elements of the tectorial membrane are derived from interdental cells was obtained. In the basilar membrane, no HSPG, chondroitin sulfate (Chs), or collagens (type I and IV) were detected. The unique structures containing these substances reacted strongly with anti-HS (heparan sulfate), anti-HSPG-CP (core protein) and anti-collagen (type I and IV) antibodies that developed in the middle layer of the stria vascularis after the administration of CDDP. However, no change was observed in the tectorial membrane, the spiral prominence, the basilar membrane, or the spiral limbus. The decrease in HSPG in cells of the organ of Corti, and the changes in the stria vascularis, may help solve the well known contradiction between the severity of morphological damage and of the hardness of hearing.