Studies of stable voluntary intake of ethanol induced by intermittent ethanol exposure.

Male rats were exposed to ethanol 2 days each week for 57 weeks. The basic concept behind this treatment was that human alcoholism in Nordic countries could be caused in susceptible individuals by an exposure pattern consisting of mainly weekend drinking which is prevalent in that society. More continous daily exposure was also used as example of a different pattern. The changes induced by these exposures were evaluated with a preference test. In this preference test (3 week periods) it was found that the "weekend" treated rats voluntarily selected individually defined doses irrespectively of the concentration of ethanol (5-25 per cent) offered in the preference test. A first biochemical screening based on earlier results with ethanol revealed an increased number of muscarinic binding sites at sacrifice in the rats which had had the "weekend" treatment.