Saccharin consumption and the effect of a long-term exposure to a sweetened alcoholic solution in high- (UChB) and low- (UChA) alcohol-drinking rats

Tampier, Lutske; Quintanilla, María Elena

doi:10.1016/j.alcohol.2005.10.002

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Volume 37, Issue 1 , Pages 47-52, August 2005

Saccharin consumption and the effect of a long-term exposure to a sweetened alcoholic solution in high- (UChB) and low- (UChA) alcohol-drinking rats

Program of Molecular and Clinical Pharmacology, ICBM, Faculty of Medicine, University of Chile, P.O. Box 70.000, Santiago 7, Chile

Received 30 March 2005; received in revised form 29 August 2005; accepted 5 October 2005.

Abstract

An association between saccharin consumption and alcohol intake has been observed in rodent lines genetically developed for alcohol preference or alcohol avoidance. It has also been proposed that a sweetened alcohol solution can condition rats to consume high amounts of alcohol. This work had two aims. First, to study the relationship between saccharin and alcohol intake in both high-alcohol-drinking UChB rats and low-alcohol-drinking UChA rats and, second, to determine whether a long-term exposure to a sweetened alcohol solution can increase their voluntary alcohol consumption. For the first purpose, UChB and UChA rats were tested under a free-choice paradigm between two graduated bottles, one containing a saccharin solution (0.1, 0.2, or 0.4% [wt/vol]) and the other water. For the second purpose, UChB and UChA rats that were under free choice between 10% alcohol and water, were offered a 10% alcohol solution containing 0.2% saccharin, instead of 10% alcohol for 1 month and were then returned to free choice between 10% alcohol and water. The first experiment showed that both lines have a high preference for saccharin at any concentration, but UChB rats drank twice as much saccharin solution as UChA rats and consequently they increased significantly their total daily fluid intake. This fact has been suggested to be an animal analogue of the clinical phenomenon known as “loss of control.” In the second experiment a long-term exposure to a 10% alcohol solution containing 0.2% saccharin induced a significant increase in alcohol consumption in UChB rats once saccharin was faded out, whereas the alcohol consumption in UChA rats returned to the previous low value. This result indicates that UChA rats have a genetic predisposition to avoid alcohol. In conclusion, the results reported here for UChB and UChA rats show an association between saccharin and alcohol preference, and suggest that their different genotypes are probably involved in alcohol aversion.

Keywords: UChA and UChB rats, Alcohol intake, Saccharin preference, Alcohol aversion