Nakazawa K, Spicer S S, Schulte B A
Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston 29425, USA.
Hear Res. 1995 Jan;82(1):93-9. doi: 10.1016/0378-5955(94)00162-j.
The fifth isoform from the family of facilitative glucose transporters (GLUT 5) was identified in the gerbil cochlea by light and electron microscopic immunohistochemistry. The immunostaining procedure employed a polyclonal antibody raised against a synthetic peptide representing the carboxy terminus of human GLUT 5. Immunoreactive GLUT 5 was abundant in the basolateral plasma membrane of outer hair cells (OHCs) in the mature gerbil cochlea. No immunostaining was observed in any other site in the cochlea or vestibular system. During postnatal development of the gerbil inner ear, OHCs were first observed to express GLUT 5 in a punctate pattern at 10 days after birth. Immunostaining intensity increased gradually and developed a linear pattern along the entire OHC basolateral plasmalemma between 10 and 16 days after birth when it approached adult levels. The developmental expression of GLUT 5 corresponded with the appearance of glycogen in OHCs and structural maturation of the organ of Corti. This time period also coincided with the onset and rapid maturation of auditory function in the gerbil. GLUT 5 apparently supports OHC function by facilitating uptake of glucose which enables these cells to sustain a high level of metabolic activity in a relatively anaerobic environment.
通过光镜和电镜免疫组织化学技术，在沙鼠耳蜗中鉴定出了易化性葡萄糖转运蛋白家族（GLUT 5）的第五种异构体。免疫染色过程使用了一种针对代表人类GLUT 5羧基末端的合成肽产生的多克隆抗体。在成熟沙鼠耳蜗的外毛细胞（OHC）基底外侧质膜中，免疫反应性GLUT 5丰富。在耳蜗或前庭系统的任何其他部位均未观察到免疫染色。在沙鼠内耳的出生后发育过程中，出生后10天时首次观察到OHC以点状模式表达GLUT 5。免疫染色强度逐渐增加，并在出生后10至16天沿着整个OHC基底外侧质膜形成线性模式，此时接近成年水平。GLUT 5的发育表达与OHC中糖原的出现以及柯蒂氏器的结构成熟相对应。这个时间段也与沙鼠听觉功能的开始和快速成熟相吻合。GLUT 5显然通过促进葡萄糖摄取来支持OHC功能，这使这些细胞能够在相对厌氧的环境中维持高水平的代谢活动。
