Carroll M E, Meisch R A
Pharmacol Biochem Behav. 1979 Jan;10(1):155-9. doi: 10.1016/0091-3057(79)90182-5.
One group of free-feeding rats was given a 5 microgram/ml etonitazene HCl solution as their sole liquid. This group increased their drug intake by 100% when they were partially food-deprived during a 23-day period. Another group that remained food-satiated and received etonitazene for an equal number of days did not show similar increases in drug intake. However, this group drank greater volumes of the etonitazene solution than a food-satiated control group drank of water. These results are contrasted with a fourth group showing a 50% decrement in water intake during similar food-deprived conditions. The food-deprived group drinking etonitazene showed highly erratic drinking patterns compared to all the other groups. Daily liquid intake ranged from 30 to 250 ml in this group, and volumes oscillated from high to low on alternating days. When the food-deprived/food-satiated conditions were replicated in this experimental group, corresponding increases and decreases in drinking reliably occurred. However, during the second food-deprived phase, the large increases occurred almost immediately as contrasted with a gradual increase over 17 days during the first food-deprived phase. This would suggest a learning mechanism may be involved. Self-mutilation and other forms of stereotypy were noted only in food-deprived rats consuming etonitazene.
一组自由进食的大鼠被给予浓度为5微克/毫升的盐酸依托尼嗪溶液作为其唯一的液体。在为期23天的部分食物剥夺期间，该组大鼠的药物摄入量增加了100%。另一组保持食物充足且接受依托尼嗪的天数相同的大鼠，其药物摄入量并未出现类似的增加。然而，该组大鼠饮用的依托尼嗪溶液量比食物充足的对照组饮用的水量要多。这些结果与第四组形成对比，第四组在类似的食物剥夺条件下饮水量减少了50%。与所有其他组相比，饮用依托尼嗪的食物剥夺组表现出高度不稳定的饮水模式。该组大鼠每日液体摄入量在30至250毫升之间，且摄入量在隔天从高到低波动。当在该实验组中重复食物剥夺/食物充足条件时，饮水量相应地可靠地出现增加和减少。然而，在第二个食物剥夺阶段，与第一个食物剥夺阶段17天内的逐渐增加相比，大幅增加几乎立即出现。这表明可能涉及一种学习机制。仅在食用依托尼嗪的食物剥夺大鼠中观察到自残和其他形式的刻板行为。
