Agabio R, Carai M A, Lobina C, Pani M, Reali R, Bourov I, Gessa G L, Colombo G
Bernard B. Brodie Department of Neuroscience, University of Cagliari, Italy.
Alcohol Clin Exp Res. 2000 Jan;24(1):24-9.
It has been proposed that ethanol intake and consumption of sweet tasting solutions are positively correlated in rodents. Experiment 1 of the present study investigated whether selectively bred ethanol-preferring (sP) and -nonpreferring (sNP) rats differed, consistently with the above hypothesis, as to saccharin intake and preference. Experiment 2 evaluated whether saccharin addition to the ethanol solution, likely resulting in a highly palatable fluid, would result in an increase in voluntary ethanol intake in sP rats.
The saccharin solution was offered, in free choice with water, at a fixed concentration of 1 g/liter for 6 consecutive days in Experiment 1A or at ascending concentrations (0.002 to 16.4 g/liter, doubling the concentration every day) in Experiment 1B. In Experiment 2, 1 g/liter saccharin was added to the standard 10% ethanol solution and offered to sP rats in free choice with water for 7 consecutive days.
In both Experiments 1A and 1B, sP and sNP rats showed avidity for the saccharin solution with marginal line difference in saccharin intake and preference. In Experiment 2, daily ethanol intake remained stable at baseline levels (6-7 g/kg), irrespective of the saccharin addition to the ethanol solution.
The results of Experiments 1A and 1B suggest that saccharin drinking behavior in sNP rats deviates from the hypothesis that saccharin and ethanol intakes may co-vary; thus, at least in sNP rats, saccharin and ethanol intakes do not appear to be influenced by the same genetic factors. The results of Experiment 2 provide further support to the existence of a central set-point mechanism that regulates daily ethanol intake in sP rats, likely based on the pharmacological effects of ethanol.
有人提出，在啮齿动物中，乙醇摄入量与甜味溶液的消耗量呈正相关。本研究的实验1调查了选择性培育的嗜乙醇（sP）和非嗜乙醇（sNP）大鼠在糖精摄入量和偏好方面是否与上述假设一致存在差异。实验2评估了在乙醇溶液中添加糖精（可能会产生一种非常可口的液体）是否会导致sP大鼠的自愿乙醇摄入量增加。
在实验1A中，以1克/升的固定浓度连续6天提供糖精溶液，让其与水自由选择；在实验1B中，以递增浓度（0.002至16.4克/升，每天浓度翻倍）提供。在实验2中，向标准的10%乙醇溶液中添加1克/升糖精，并连续7天提供给sP大鼠，让其与水自由选择。
在实验1A和1B中，sP和sNP大鼠都表现出对糖精溶液的喜好，在糖精摄入量和偏好方面存在微小的差异。在实验2中，无论乙醇溶液中是否添加糖精，每日乙醇摄入量都保持在基线水平（6 - 7克/千克）稳定。
实验1A和1B的结果表明，sNP大鼠的糖精饮用行为偏离了糖精和乙醇摄入量可能共同变化的假设；因此，至少在sNP大鼠中，糖精和乙醇摄入量似乎不受相同遗传因素的影响。实验2的结果进一步支持了存在一种中枢设定点机制来调节sP大鼠每日乙醇摄入量的观点，这可能基于乙醇的药理作用。
