Experimentally induced glucose intolerance increases oral ethanol intake in rats

A number of studies have shown a relationship between glucose tolerance and ethanol intake. The present study uses a relatively simple procedure to induce glucose intolerance to test whether this condition is sufficient to produce an increase in chronic ethanol intake in male rats. Subjects were divided equally into four groups where they were given access to one of four solutions: peppermint-flavored sucrose (40%), peppermint-flavored saccharin (0.1%), peppermint in water (0.1%), or water alone presented three times a week, for a period of 11 weeks. After 12 weeks all animals were subjected to an oral glucose tolerance test which revealed that the chronically prepared sucrose animals had become glucose intolerant. At the start of week 13 all animals were given access to a 6% ethanol solution flavored with peppermint in place of the previous solutions for a period of 11 weeks. Sucrose animals displayed an immediate preference for ethanol and consumed approximately three times more ethanol than the remaining groups. The results of this study indicate that rats that are made glucose intolerant by long term access to a high concentration of sucrose, when given the opportunity, will subsequently choose to drink more ethanol than control animals.