Effects of thirst-inducing stimuli on consumption of ethanol solutions by golden hamsters.

Two experiments were performed to examine the acute effects of thirst-inducing stimuli upon the intake of tap water and ethanol solutions by golden hamsters, a species which avidly consumes ethanol solutions. In Experiment 1, three groups of adult male hamsters (n = 6/group) were maintained on Purina chow and tap water; hamsters in two of the groups also had access to one of two ethanol solutions (15% or 30%, v/v). Animals were deprived at various times of either one or both fluids for 24 hr, and then either one or both fluids were presented during a 2-hr drinking test. Total water intake increased substantially following both selective water deprivation and total fluid deprivation whenever tap water was available during the drinking test, but no significant changes occurred when only the ethanol solution was available. Both total fluid deprivation and selective ethanol deprivation produced similar increases in ethanol consumption, but selective water deprivation did not, suggesting that the temporary removal of tap water has little direct effect upon ethanol intake in hamsters, at least at the ethanol concentration levels studied here. In Experiment 2, thirst was induced by a subcutaneous injection of 10% saline (1 ml/100 g). This procedure produced large increases in total water intake whenever tap water was available during the drinking test, but ethanol intake did not change under any circumstances. These results suggest that factors that acutely enhance water intake have little or no effect upon the ethanol consumption of golden hamsters.