Harpur E S, D'Arcy P F
J Pharm Pharmacol. 1975 Dec;27(12):907-13. doi: 10.1111/j.2042-7158.1975.tb10246.x.
Twelve male Lister hooded rats were conditioned to discriminate an 8 kHz tone (56.5 +/- 0.5 dB re 0.0002 dyne cm-2) and were subsequently injected subcutaneously with kanamycin (400 mg kg-1 day-1) for 28 days; during this time and for five weeks after dosage was stopped, the nature and extent of the resultant hearing deficits were studied. The animals' Preyer reflex thresholds were determined at intervals during the study. Only one rat was unaffected by the kanamycin dosage. The onset of hearing impairment (reduced discrimination performance), which was gradual in some rats and sudden in others, generally occurred during the fourth week of kanamycin dosage although the earliest onset was towards the end of the second week. In most animals the hearing impairment progressed after kanamycin was stopped and in one rat there was a latency between the end of drug dosage and onset of hearing impairment. Hearing impairment was irreversible in five rats. One rat, whose impairment was slight, recovered normal hearing. Some rats showed a reduced discrimination performance at a time when their Preyer reflex threshold showed no elevation suggesting that kanamycin, at least initially, caused a threshold elevation rather than reduced sensitivity to intense sounds.
选用12只雄性利斯特品系的带帽大鼠，训练它们辨别8千赫的纯音（56.5±0.5分贝，参考声压为0.0002达因/平方厘米），随后皮下注射卡那霉素（400毫克/千克/天），持续28天；在此期间以及停药后的五周内，研究由此产生的听力缺陷的性质和程度。在研究过程中定期测定动物的普雷耶反射阈值。只有一只大鼠未受卡那霉素剂量的影响。听力障碍的发作（辨别能力下降），在一些大鼠中是逐渐发生的，在另一些大鼠中是突然发生的，通常发生在卡那霉素给药的第四周，尽管最早发作是在第二周快结束时。在大多数动物中，卡那霉素停药后听力障碍仍在进展，并且有一只大鼠在药物给药结束与听力障碍发作之间存在潜伏期。五只大鼠的听力障碍是不可逆的。一只大鼠的听力障碍较轻，恢复了正常听力。一些大鼠在普雷耶反射阈值没有升高的时候就表现出辨别能力下降，这表明卡那霉素至少在最初阶段导致了阈值升高，而不是对高强度声音的敏感度降低。
