Dietary salt and voluntary ethanol consumption in golden hamsters

Adult male golden hamsters were maintained on powdered Purina chow and tap water, and were permitted continuous access to either a 15% or a 30% ethanol solution (v/v); after an initial 4-5 weeks of ethanol availability, hamsters had stabilized their intakes and were deriving an average of 1.25 and 1.96 g/day of absolute ethanol from the 15% and 30% solutions, respectively. When salt was added to the diet in increasing concentrations ranging from 4% to 10% over a period of 40 days, hamsters reduced chow-derived calories by up to 35%, increased tap water consumption by up to 50%, and increased consumption of ethanol solutions by up to 100%; when unadulterated Purina chow was reinstated, intakes of chow-derived calories, tap water, and ethanol solutions returned to baseline levels. Hamsters that were continuously maintained on unadulterated Purina chow, but with chow-derived calories matched to that of animals on the salt-adulterated diet, significantly increased their ethanol intake, but not their tap water intake; the increase in their ethanol intake was only about half as large as that of hamsters that had salt added to the diet, but the increase persisted even after ad lib feeding was reinstated. The results indicate that the addition of salt to the diet of hamsters produces large increases in ethanol consumption; furthermore, the increased ethanol intake is not simply the result either of a nonselective increase in fluid consumption or of the reduction in food intake that accompanies the addition of salt to the diet. Results are related to the possible role of the renin-angiotensin system in the control of ethanol consumption in the golden hamster.