Effect of quipazine, a selective 5-HT3agonist, on dietary self-selection of different macronutrient diets in male and female rats

Macronutrient intakes, 2 h and 12 h, following administration of a selective 5-HT3agonist, quipazine, N methyl, dimaleate (QUIPAZINE; 2·5, 5·0 and7·5 mg/kg, i.p.) at dark onset were examined in three groups of adult male and female Wistar rats fed different sources of the three macronutrients: Group 1 (casein, corn starch, safflower oil), Group 2 (egg protein, corn starch/sucrose, lard) and Group S (casein hydrolysate, maltose dextrin, butter). QUIPAZINE decreased total food intake only in female rats from Group 1 (2 h) at a dose of 7·5 mg/kg and Group 2 (2 h and 12 h) with doses of 2·5 and 7·5 mg/kg. Intakes from corn starch and corn starch/sucrose diet (12 h) were reduced in male and female rats, respectively, with doses of 2·5 and 7·5 mg/kg of QUIPAZINE. In conclusion, when provided with different sources of the three macronutrients, quipazine injection reduces specifically carbohydrate ingestion from corn starch-containing diets in male and female rats. Thus, the nature of the macronutrient source is of major importance to assess the effect of a drug on nutrient-specific selection.