Blair-West J R, Denton D A, McBurnie M I, Weisinger R S
Howard Florey Institute of Experimental Physiology and Medicine, University of Melbourne, Parkville, Victoria, Australia.
Physiol Behav. 1996 Aug;60(2):481-7. doi: 10.1016/s0031-9384(96)80022-9.
Mice that were habituated to drinking ethanol solution and mice that had drunk water only (naive mice) were given an ICV infusion of angiotensin II (Ang II) at 2.9 ng/h for 8 days to determine the effect of chronic ethanol intake on the ingestive response to this potent dipsogen. Ang II infusion in alcohol-naive mice increased daily water intake from 3.7 +/- 0.2 ml (mean +/- SE, n = 6) to 11.0 +/- 1.5 ml on day 4 (p < 0.001) and to 18.3 +/- 2.6 ml on day 8 (p < 0.001). In subsequent experiments, mice had access to 4% ethanol solution up to day 4 and then to water for 4 days during the Ang II infusion. Alcohol-naive mice did not increase daily fluid intake until the water was provided on day 5; intake increased to 17.5 +/- 2.3 ml on day 8 (p < 0.001, n = 7). Mice accustomed to drinking 4% ethanol (4.3 +/- 0.3 ml/day) also did not increase intake until the water was provided; intake reached 22.9 +/- 3.0 ml of water on day 8 (p < 0.001, n = 7). Mice accustomed to drinking 10% ethanol behaved similarly (n = 4). Thus, alcohol-naive or -habituated mice did not respond to this dipsogenic stimulus until water was available; the thirst for water was unimpaired. Preference-aversion tests showed that mice drank little or no 4% ethanol (or even 2% ethanol) when water was also available. Taste aversion, plus previous experience from ingestion of ethanol in habituated mice, may explain the rejection of ethanol to quench Ang II-induced thirst. Experimental results obtained using other aversive solutions, 3 mM quinine and 300 mM KCl, suggest that postingestional, metabolic effects of solutes may also contribute to such rejection.
将习惯饮用乙醇溶液的小鼠和只饮用清水的小鼠（未接触过乙醇的小鼠）以2.9纳克/小时的速度脑室内注射血管紧张素II（Ang II），持续8天，以确定长期摄入乙醇对这种强效致渴剂引起的摄食反应的影响。给未接触过乙醇的小鼠注射Ang II后，其每日饮水量从3.7±0.2毫升（平均值±标准误，n = 6）在第4天增加到11.0±1.5毫升（p < 0.001），在第8天增加到18.3±2.6毫升（p < 0.001）。在随后的实验中，小鼠在第4天之前可以自由饮用4%的乙醇溶液，然后在注射Ang II期间的后4天改为饮用清水。未接触过乙醇的小鼠直到第5天提供清水时才增加每日液体摄入量；第8天摄入量增加到17.5±2.3毫升（p < 0.001，n = 7）。习惯饮用4%乙醇（4.3±0.3毫升/天）的小鼠在提供清水之前也没有增加摄入量；第8天清水摄入量达到22.9±3.0毫升（p < 0.001，n = 7）。习惯饮用10%乙醇的小鼠表现类似（n = 4）。因此，未接触过乙醇或已习惯乙醇的小鼠在有清水之前对这种致渴刺激没有反应；对水的渴感未受损害。偏好-厌恶测试表明，当有清水时，小鼠很少饮用或不饮用4%的乙醇（甚至2%的乙醇）。味觉厌恶，加上习惯摄入乙醇的小鼠以前的摄入经验，可能解释了它们拒绝饮用乙醇来缓解Ang II诱导的口渴。使用其他厌恶溶液3 mM奎宁和300 mM氯化钾获得的实验结果表明，溶质的摄入后代谢效应也可能导致这种拒绝行为。
