Effects of sweetened ethanol solutions on ethanol self-administration and blood ethanol levels.
The enhancement of voluntary self-administration of ethanol by sucrose or saccharin was tested in conjunction with measurements of blood ethanol levels. Adult male rats were given access to both tap water and one of five solutions: 0.125% saccharin, 10% sucrose, ethanol, saccharin+ethanol, or sucrose+ethanol. The rats receiving the sucrose+ethanol solution drank consistently more ethanol (>5 g/kg/day) than did the rats receiving the saccharin+ethanol solution (<3 g/kg/day) or ethanol only (<2 g/kg/day). Both sweetened solutions produced higher ethanol consumption during these periods than ethanol alone. However, no significant differences in blood ethanol levels were found between the sucrose+ethanol and saccharin+ethanol conditions, when tested at different intervals on Day 44 or Day 45 of ethanol consumption. Following 45 days of consumption, no change in the bicuculline seizure threshold was observed in the ethanol-consuming rats compared to the controls. In a separate study using 90 naive rats, rats were gavaged with ethanol (1, 2, or 3 g/kg) containing either 10% sucrose (n=10 for each dose of ethanol), 0.125% saccharin (n=10 for each dose of ethanol), or ethanol alone (n=10 for each dose of ethanol), and blood was collected from the tip of the tail 30, 60, 180, 300, and 540 min later and analyzed for ethanol concentrations. Sucrose significantly decreased the resultant blood ethanol levels at several time points following gavage. These results indicate that sucrose can significantly alter blood ethanol levels and that chronic self-administration of a sweetened ethanol solution for 6 weeks does not produce ethanol dependence.