Foong F W, Satoh M, Takagi H
J Pharmacol Methods. 1982 Jun;7(4):271-8. doi: 10.1016/0160-5402(82)90080-8.
A pain-producing substance, bradykinin (0.63--1.25 ng in 0.5--1.0 microliter of distilled water), was applied onto the tooth pulp of the lower incisor of unrestrained rats through a cannula fixed on the surfaces of the incisors using a microsyringe. Such a microapplication of bradykinin induced biting response and other aversive behaviors. When the microapplications were repeated at intervals of 60 min, the biting response seemed most characteristic and reproducible. Therefore, the duration of biting response was used as a measure in studying the effects of drugs on trigeminal pain. If biting duration was inhibited 90% or more after drug administration the effect was considered analgesic. Carbamazepine and phenytoin, which are clinically employed for treating trigeminal neuralgia, and morphine, a narcotic analgesic, produced dose-dependent analgesic effects in this method and the corresponding ED50 values were 13.1 intraperitoneally (ip), 75.0 ip, and 3.00 subcutaneously (sc) mg/kg, respectively. On the other hand, pentobarbital (15 mg/kg, ip), diazepam (1.0 mg/kg, ip), and aspirin (150 mg/kg, ip) were not effective in suppressing the biting response. These results indicate that this newly devised method in the rat is reliable and feasible in evaluating pain related the trigeminal system.
一种能产生疼痛的物质，缓激肽（在0.5 - 1.0微升蒸馏水中含0.63 - 1.25纳克），通过固定在大鼠下切牙表面的套管，用微量注射器注射到未束缚大鼠的牙髓上。这种微量注射缓激肽会引发咬啮反应和其他厌恶行为。当每隔60分钟重复进行微量注射时，咬啮反应似乎最具特征且可重复。因此，咬啮反应的持续时间被用作研究药物对三叉神经痛影响的一个指标。如果给药后咬啮持续时间被抑制90%或更多，则认为该药物有镇痛作用。临床上用于治疗三叉神经痛的卡马西平和苯妥英，以及麻醉性镇痛药吗啡，在此方法中均产生剂量依赖性镇痛作用，相应的腹膜内（ip）半数有效剂量（ED50）值分别为13.1、75.0毫克/千克，皮下（sc）为3.00毫克/千克。另一方面，戊巴比妥（15毫克/千克，ip）、地西泮（1.0毫克/千克，ip）和阿司匹林（150毫克/千克，ip）在抑制咬啮反应方面无效。这些结果表明，这种新设计的大鼠实验方法在评估与三叉神经系统相关的疼痛方面是可靠且可行的。
