Abstract

The effects of the catalase inhibitor 3-amino-1,2,4-triazole (AT) were examined on ethanol, food and water intakes to determine if it produced a decrease in ethanol consumption through the decrease in catalase produced acetaldehyde or to a general decrease in caloric intake. Experiment 1A demonstrated that a food containing a concentration of 0.6% w/w sodium saccharin was preferred over a neutral-flavoured food while a concentration of 0.15% w/w of quinine sulfate was less preferred. These two concentrations of saccharin and quinine were used in experiment 1B to study the effects of AT on taste reactivity. Results of experiment 1B showed that AT significantly decreased food intake but not ethanol water or total fluid intakes. The saccharin, neutral and quinine food groups decreased their food intakes to the same extent suggesting that AT did not affect taste reactivity. Furthermore, quinine-fed rats significantly increased their ethanol consumption while decreasing their food and water intakes. Experiment 1C tested whether the quinine-induced changes in ethanol, food and water intakes were mediated through the 5-$\rm HT\sb2$ receptor. The 5-$\rm HT\sb2$ antagonist ritanserin failed to attenuate the quinine-induced ethanol consumption or to affect food or water intakes. Experiment 2 showed that AT significantly decreased ethanol consumption but did not significantly affect either food or water intake. Taken together, the findings of experiments 1B and 2 demonstrated that AT does not produce a general decrease in the caloric requirement of the animal. The failure of AT to decrease ethanol consumption in experiment 1B is contradictory to previous reports regarding the role of catalase produced acetaldehyde and its role in the mediation of ethanol intake. However, the decrease in ethanol intake observed in experiment 2 is consistent with the pattern of catalase inhibition suggesting that acetaldehyde may be involved in the mediation of voluntary ethanol consumption.