Auditory evoked potentiometer
The purpose of this study was to observe the ototoxic effects of kanamycin sulfate (KM) on adult rats. Forty male Sprague-Dawley (SD) rats aged 6 to 7 weeks were randomly divided into two groups: the experimental group, intraperitoneal injection of KM (500 mg / kg) for 2 weeks each day: the control group, injection of the same amount of normal saline for 2 weeks. The auditory brainstem response (ABR) was measured to observe the hearing changes in rats. After the ABR test was completed, the cochlea was isolated for basement membrane smear and cochlear frozen section, and the density and cochlear morphology of spiral ganglion cells (SGCs) were observed. The results showed that after 2 weeks of KM injection, the auditory thresholds of rats in each frequency increased significantly, and the increase range was more than 60dB. Over time, the density of SGCs in the KM group gradually decreased, and the structure of the Corti organ remained, but the outer hair Both cells and inner hair cells were deleted to varying degrees, with outer hair cells being even worse; inner hair cell deletion was parallel to the decrease in density of SGCs. The above results indicate that, after 6 weeks of KM effect in 6-7 week old rats, hearing will be significantly reduced, and severe deafness or even deafness will be achieved. Ototoxicity of KM is closely related to the damage of SGCs and inner and outer hair cells.