Myers R D
Brain Res Bull. 1981 Aug;7(2):209-20. doi: 10.1016/0361-9230(81)90085-x.
A series of five experiments was undertaken in order to characterize the pharmacological effects of alcohol on the body temperature of the unrestrained rat. After a thermistor probe was fixed within the colon of each animal and its body temperature had stabilized, physiological saline. 2.0 g/kg or 4.0 g/kg of ethyl alcohol was given by intragastric gavage. A constant concentration of 20% was utilized with doses determined volumetrically according to the individual weight of the animal. The following observations were made: (1) At a laboratory room temperature of 22 degrees C, alcohol produced a dose-dependent decline in colonic temperature. This fall was enhanced when the rat was placed in a chamber with an ambient temperature of 8 degrees C, but reversed into a hyperthermic response when the ambient temperature of the rat was elevated to 36 degrees C. (2) If the rat was exposed for one hour to either a warm (36 degrees C) or cold (8 degrees C) ambient temperature beginning at the time of the intragastric gavage with alcohol, the body temperature of the animal correspondingly decreased or increased, respectively. The magnitude of the shift in the animal's colonic temperature depended solely on the dose of alcohol given, i.e., thermolability was enhanced to a greater extent by the r.0 g/kg dose than the 2.0 g/kg dose. Exposure of the rat to a high or low ambient temperature prior to intragastric gavage with alcohol also affected the body temperature displacement as well as the direction of change. (3) Following the 4.0 g/kg alcohol dose, the animal's colonic temperature could be controlled precisely by varying the ambient temperatures in the 26 degrees C--32 degrees C range of thermoneutrality; in fact, within limits, the rat's temperature could be held constant at any predetermined level. (4) Pretreatment of the animal with 6.0 ml of a 50% solution of glucose given subcutaneously failed to attenuate the poikilothermic effect of intragastric alcohol administered in a dose of 4.0 g/kg. (5) Comparisons of the effect on body temperature of equipotent doses of sodium pentobarbital (25 mg/kg), administered intraperitoneally, and alcohol (4.0 g/kg) given by gavage showed that either a high or low ambient temperature elevated or lowered the colonic temperature of the rat at an identical rate and magnitude. It is concluded that alcohol acts acutely as any other anesthetic agent to abolish all thermoregulatory control functions. Thus, the physiological mechanisms for the dissipation of body heat as well as those for heat production are incapacitated by the drug. Clearly, alcohol is a poikilothermic agent, and thus, the decline in body temperature observed in the animal typically kept at a laboratory room temperature of 20 degrees C--24 degrees C represents the result of a cold challenge and is not due to a postulated "hypothermic" effect of alcohol.
进行了一系列五项实验，以表征酒精对无束缚大鼠体温的药理作用。在将热敏电阻探头固定在每只动物的结肠内且其体温稳定后，给予生理盐水、2.0 g/kg或4.0 g/kg的乙醇灌胃。使用20%的恒定浓度，剂量根据动物个体体重按体积确定。得出以下观察结果：(1) 在实验室室温22摄氏度时，酒精使结肠温度呈剂量依赖性下降。当大鼠置于环境温度为8摄氏度的箱中时，这种下降会增强，但当大鼠的环境温度升至36摄氏度时，会转变为体温过高反应。(2) 如果在给酒精灌胃时开始将大鼠暴露于温暖（36摄氏度）或寒冷（8摄氏度）的环境温度下一小时，动物的体温相应地分别下降或上升。动物结肠温度变化的幅度仅取决于给予的酒精剂量，即4.0 g/kg剂量比2.0 g/kg剂量在更大程度上增强了体温易变性。在给酒精灌胃前将大鼠暴露于高或低环境温度下也会影响体温变化以及变化方向。(3) 在给予4.0 g/kg酒精剂量后，通过在26摄氏度至32摄氏度的热中性范围内改变环境温度，可以精确控制动物的结肠温度；实际上，在一定范围内，大鼠的体温可以保持在任何预定水平不变。(4) 在皮下给予动物6.0 ml 50%的葡萄糖溶液进行预处理，未能减弱给予4.0 g/kg剂量灌胃酒精的变温效应。(5) 对腹腔注射等效剂量的戊巴比妥钠（25 mg/kg）和灌胃给予酒精（4.0 g/kg）对体温的影响进行比较，结果表明，高或低环境温度以相同的速率和幅度升高或降低大鼠的结肠温度。得出的结论是，酒精作为任何其他麻醉剂一样，急性作用是消除所有体温调节控制功能。因此，药物使身体散热以及产热的生理机制丧失能力。显然，酒精是一种变温剂，因此，在通常保持在实验室室温20摄氏度至24摄氏度的动物中观察到的体温下降代表寒冷刺激的结果，而不是由于假定的酒精“低温”效应。
