Wright C G, Meyerhoff W L, Halama A R
Department of Otorhinolaryngology, University of Texas Health Science Center, Dallas.
Am J Otol. 1987 Nov;8(6):495-9.
Previous experimental studies have demonstrated structural damage of the organ of Corti and stria vascularis following application of combination antibiotic otic drops to the middle ear. In this investigation the ototoxic effects of neomycin and polymyxin B (two antibiotics often used together in ototopical preparations) were separately evaluated after administration of each agent to the middle ear cavities of chinchillas and baboons. The antibiotics were administered in saline solution at the same concentrations used in Cortisporin Otic Suspension (3.5 mg/ml neomycin base, 10,000 units/ml polymyxin B). In both the rodent and primate, polymyxin B consistently produced greater cochlear damage than did neomycin. In fact, the extent of hair cell loss and strial injury produced by polymyxin B alone was, in many cases, comparable to that previously observed after application of Cortisporin Otic Suspension itself. Hair cell loss in the baboon was markedly less severe than in the chinchilla. It is believed that differences in position and structure of the round window membrane are important factors in the differing levels of ototoxicity observed in the rodent and primate.
先前的实验研究表明，向中耳应用复方抗生素耳用滴剂后，柯蒂氏器和血管纹会出现结构损伤。在本研究中，在将新霉素和多粘菌素B（两种常用于耳用制剂的抗生素）分别施用于龙猫和狒狒的中耳腔后，对其耳毒性作用进行了评估。抗生素以与可的舒耳用混悬液相同的浓度溶于盐溶液中给药（新霉素碱3.5毫克/毫升，多粘菌素B 10000单位/毫升）。在啮齿动物和灵长类动物中，多粘菌素B始终比新霉素产生更大的耳蜗损伤。事实上，仅多粘菌素B所导致的毛细胞损失和血管纹损伤程度，在许多情况下，与先前应用可的舒耳用混悬液后观察到的损伤程度相当。狒狒中的毛细胞损失明显不如龙猫严重。据信，圆窗膜的位置和结构差异是在啮齿动物和灵长类动物中观察到不同程度耳毒性的重要因素。
