Snow A E, Horita A
J Pharmacol Exp Ther. 1982 Feb;220(2):335-9.
Apomorphine-induced hyperthermia in the rabbit was shown to be dependent upon the presence of stressors. Two types of stressors were used: 1) a physical stressor, foot shock; and 2) an emotional stressor, conditioned fear. Apomorphine (4 mg/kg i.v.), in the absence of a stressor, produced behavioral responses of arousal, stereotypic gnawing and hind foot thumping. Foot shock, which in control animals exerted no temperature effects, when paired with apomorphine administration, produced a hyperthermic response of 1.3 degrees C. This hyperthermia was abolished by pretreatment with diazepam (5 mg/kg i.v.) or haloperidol (50 micrograms/kg i.v.). Classical conditioning was used to provide the emotional stressor and was accomplished by pairing a tone with foot shock. After conditioning the tone combined with apomorphine produced an increase in temperature of 1.3 degrees C, whereas the tone paired with saline (1 ml/kg i.v.) produced no hyperthermia. An intensity vs. effect curve was determined, and foot shock alone elicited increases of temperature in a dose-dependent manner. At a given shock intensity, apomorphine elicited a much greater response than shock alone and also decreased the threshold for response to shock. Our findings firmly establish the hypothesis that apomorphine elicits hyperthermia in the presence of stressors by increasing sensitivity and decreasing the threshold for response to stressors.
已证明，家兔中阿扑吗啡诱导的体温过高取决于应激源的存在。使用了两种类型的应激源：1）物理应激源，足部电击；2）情绪应激源，条件性恐惧。在没有应激源的情况下，阿扑吗啡（静脉注射4毫克/千克）会引起觉醒、刻板啃咬和后足跺脚等行为反应。在对照动物中无体温影响的足部电击，与阿扑吗啡给药同时进行时，会产生1.3摄氏度的体温过高反应。这种体温过高可通过地西泮（静脉注射5毫克/千克）或氟哌啶醇（静脉注射50微克/千克）预处理而消除。采用经典条件反射来提供情绪应激源，方法是将音调与足部电击配对。条件反射后，与阿扑吗啡联合的音调会使体温升高1.3摄氏度，而与生理盐水（静脉注射1毫升/千克）配对的音调则不会引起体温过高。确定了强度与效应曲线，单独的足部电击以剂量依赖的方式引起体温升高。在给定的电击强度下，阿扑吗啡引起的反应比单独的电击大得多，并且还降低了对电击反应的阈值。我们的研究结果有力地证实了这一假设，即阿扑吗啡在有应激源存在时，通过提高敏感性和降低对应激源反应的阈值来引发体温过高。
