The effects of cadmium on the self-administration of ethanol and an isocaloric/isohedonic equivalent

During a period of baseline fluid intake recording, adult male rats were presented with a three-bottle, two-fluid choice test that offered either a 10% ethanol solution (v/v) and tap water as alternatives, or a sucrose/quinine solution and tap water as alternatives. The sucrose/quinine solution was equivalent to the ethanol solution both in terms of calories and palatability. After intakes stabilized, half of the animals from each test condition were placed on a diet containing 100 ppm cadmium and the remaining half of the animals were placed on a standard laboratory diet. After 60 days of exposure to their respective diets, all animals were presented their earlier test solutions, both in a nonchoice and choice format. The results from the choice test indicated that although cadmium treatment did not produce a clear preference for ethanol over water, cadmium exposure was associated with a significant increase in ethanol consumption. Moreover, the self-administration of the isocaloric/isohedonic equivalent (sucrose/quinine solution) was unaffected by cadmium contamination. These data are discussed in terms of their implications for both nutritional and sensory-impairment accounts of metal-related changes in the volitional intake of ethanol.