摘要
细胞凋亡对细胞增殖、器官发生和功能维持起着重要作用。一定剂量的庆大霉素连续注射，造成豚鼠前庭器官损伤。采用半薄切片，透射电镜（TEM）和TUNEL（TdT－modidedbiotin-dUTPNick-endlabeling，末端脱氧核苷酸转移酶介导的生物素标记）原位杂交技术，特异标记DNA片段3′－OH末端，原位显示凋亡细胞。在半薄切片和TEM观察中发现两种类型的细胞损伤方式：①毛细胞肿胀，胞浆空泡化，细胞体从顶端表面挤出；②毛细胞在上皮内变性，显示出细胞凋亡的形态特征，包括细胞核凝缩，核膜消失，成碎块状，并由支持细胞吞噬。原位杂交显示：细胞凋亡标记阳性细胞主要分布在上皮表层，较高水平标记主要发生于给药后第3到7天。提示细胞凋亡是内耳前庭感觉细胞损伤的一种重要方式，凋亡的主动发生可能是一种潜在的介入方式来减少氨基甙类抗生素对毛细胞造成的急性损伤，并与感觉上皮损伤后的修复过程有关。
Apoptosis plays a key role in the steady state in continuously renewing tissues. The purpose of this study was to investigate whether apoptosis was a mode of hair cell loss in mammalian inner ear sensory epithelia. Hair cell loss was induced by systematic treat-ment with ototoxic aminoglycoside antibiotic gentamicin. The vestibular sensory epithe-lia were examined at different times after administration via thin sections and in situ la-beling by the terminal deoxynucleotidyl transferase catalysis of digoxigenin tagged nu-cleotides to the free 3'-OH ends of fragmented DNA. By the transmission electron mi-croscopy, two kind of hair cell loss modes were observed: (1) swelling of the cell, vac-uolation and distortion of cell shape and extrusion of hair cells body from the apical sur-face; (2) degeneration of hair cells within the epithelium, which showed some of apop-tosis morphological changes, including condensation and fragmentation of the nucleus and modifications of cytoplasmic orgnelles. The fragments of degenerated cell body were removed through phagocytosis by supporting cells. By the in situ labeling, the ma jority of the apoptotic nuclei were found in the lumenal laryer. Most of them were clearly hair cell. Apoptotic labling was more evidentat 3 to 7 day after treatment. The resultsindicated that apoptosis was an important modes of hair cell loss of mammalian inner ear sensory epithelia. It may be a role in preventing aminolglycoside-induced cell death and also a trigger for subsequent repair and cell proliferation processes.
出处
《耳鼻咽喉（头颈外科）》
1997年第5期300-303,共4页
Chinese Arch Otolaryngology-Head Neck Surg
基金
北京市卫生局研究基金
