Kuntz A L, Oesterle E C
Department of Otolaryngology-HNS, Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle 98195, USA.
J Comp Neurol. 1998 Sep 28;399(3):413-23.
Hair cells, the sensory receptors of the mammalian inner ear, have long been thought to be produced only during embryogenesis, and postnatal hair cell loss is considered to be irreversible and is associated with permanent hearing and balance deficits. Little is known about the factors that regulate hair cell genesis and differentiation. The mitogenic effects of insulin and transforming growth factor alpha (TGFalpha) were assayed in vivo in normal and drug-damaged rat inner ear. Tritiated thymidine and autoradiographic techniques were used to identify cells synthesizing DNA. Simultaneous infusion of TGFalpha and insulin directly into the inner ear of adult rats stimulated DNA synthesis in the vestibular sensory receptor epithelium. New supporting cells and putative new hair cells were produced. Infusion of insulin alone or TGFalpha alone failed to stimulate significant DNA synthesis. These results suggest that exogenous growth factors may have utility for therapeutic treatment of hearing and balance disorders in vivo.
毛细胞是哺乳动物内耳的感觉感受器，长期以来一直被认为仅在胚胎发育期间产生，出生后毛细胞的损失被认为是不可逆的，并与永久性听力和平衡缺陷相关。关于调节毛细胞发生和分化的因素知之甚少。在正常和药物损伤的大鼠内耳中对胰岛素和转化生长因子α（TGFα）的促有丝分裂作用进行了体内测定。使用氚标记的胸腺嘧啶核苷和放射自显影技术来鉴定合成DNA的细胞。将TGFα和胰岛素同时直接注入成年大鼠内耳可刺激前庭感觉感受器上皮中的DNA合成。产生了新的支持细胞和假定的新毛细胞。单独注入胰岛素或单独注入TGFα均未能刺激显著的DNA合成。这些结果表明外源性生长因子可能对体内听力和平衡障碍的治疗有用。
