Diminished taste reactivity to saccharin following chronic administration of theophylline in rats

Under a successive increase in the concentration of saccharin adulteration, a dual effect of facilitation and inhibition on food intake was observed in normal rats. At low concentrations (0.25 to 1.5%), saccharin adulterated diets were more acceptable than the normal one with a peak at 1.0% concentration. Food intake was conversely suppressed at a high concentration (3.0%). On exposure to either 1.0 or 3.0% saccharin diet, this facilitatory or inhibitory effect disappeared with chronic administration of theophylline. This diminution of acceptance or rejection response to saccharin was interpreted to be an impairment of taste discrimination induced by theophylline.