Synthesis of Carbohydrate Complex and its Significant Role in the Vestibular Specialized Cells

为了揭示前庭功能障碍的早期变化，本研究对前庭终末器官糖复合体的合成过程及其在前庭末梢器官中的重要作用进行了研究。前庭感觉上皮的表面，包括感觉细胞、支持细胞、移行细胞和暗细胞，被模糊的糖萼层所覆盖。研究表明，糖萼的重要作用是保持纤毛成束排列，参与感觉细胞转导系统，与内淋巴离子环境的控制机制有关，并对支持细胞的保护起重要作用。用金标记的凝集素也证明了碳水化合物复合体的超微结构定位。已有研究表明，糖萼及其伴生结构含有N-乙酰氨基葡萄糖、半乳糖、甘露糖和唾液酸。因此，这些糖可能与糖萼的不同功能密切相关。在耳毒性给药、内淋巴积水、声过度刺激等病理条件下，前庭感觉上皮细胞退变的第一步是糖基化反应减少或糖类复合体的改变。纤毛的进一步退化，如纤毛的融合、排列紊乱和消失，都是由于糖萼的损伤所致。

The synthesizing process of the carbohydrate complex and its significant role in the vestibular end organs were investigated in order to reveal the early changes in the vestibular functional disorders. The surface of the vestibular sensory epithelia including sensory, supporting, transitional and dark cells, was covered by fuzzy layers of glycocalyx. It has been indicated that the significant role of the glycocalyx is to keep the cilia arranged in a bundle, to be involved in the sensory cell transduction system, to be related with the controlling mechanisms of the ionic environment of the endolymph and to play an important role for the protection of the supporting cells. The ultrastructural localization of the carbohydrate complexes were also demonstrated using gold-labelled lectins. It has been indicated that the glycocalyx and its associated structures contain N-acetyl-glucosamine, galactose, mannose and sialic acid. These sugars may thus be closely related to the different function of the glycocalyx. In the pathological conditions such as after ototoxic drug administration, endolymphatic hydrops, acoustic overstimulation etc, the first step of degeneration process in the vestibular sensory epithelia was a decrease in glycocalyx or changes of carbohydrate complexes. The further degeneration such as fusion, disarrangement and disappearance of the cilia were all occurred as a result of the damage of glycocalyx.