Rybak L P, Whitworth C, Scott V, Weberg A
Department of Surgery, Southern Illinois University School of Medicine, Springfield 62794-9230.
Laryngoscope. 1991 Nov;101(11):1167-74. doi: 10.1288/00005537-199111000-00005.
The rat is an altricial animal which serves as a useful model for human auditory development. The purpose of the present study was to investigate the effects of furosemide on cochlear function and the stria vascularis ultrastructure at various postnatal ages. Rat pups anesthetized with ketamine hydrochloride/xylazine hydrochloride received furosemide 35 mg/kg intravenously (IV), and the endocochlear potential and compound action potential of the eighth nerve were recorded. The stria vascularis was removed and prepared for transmission electron microscopy. Rat pups 9 to 28 days of age had a much greater reduction of endocochlear potential and elevation of the compound action potential threshold than animals older than 30 days. These physiologic changes were accompanied by edema of the stria on transmission electron microscopy only in animals at susceptible ages. These findings support the concept of a critical period of susceptibility to ototoxic drugs during development and could have important clinical implications in premature infants.
大鼠是一种发育不全的动物，是研究人类听觉发育的有用模型。本研究的目的是探讨速尿对不同出生后年龄大鼠耳蜗功能及血管纹超微结构的影响。用盐酸氯胺酮/盐酸赛拉嗪麻醉的幼鼠静脉注射35mg/kg速尿，并记录第八神经的内淋巴电位和复合动作电位。取出血管纹并制备用于透射电子显微镜检查。9至28日龄的幼鼠内淋巴电位降低和复合动作电位阈值升高的幅度比30日龄以上的动物大得多。这些生理变化仅在易感年龄的动物中，在透射电子显微镜下伴有血管纹水肿。这些发现支持了发育过程中对耳毒性药物易感性关键期的概念，并且可能对早产儿具有重要的临床意义。
