Dietary selection in vagotomized rats.

Abstract

Adult female vagotomized and control (sham-vagotomized) rats were compared in their consumption of saccharin solutions, intake of solid and liquid sucrose, and selection of purified macronutrient diets. In 30 min/day tests the vagotomized rats drank more saccharin solution (0.05, 0.1, 0.2%) than did control rats, while in a 24 h/day test they drank considerably less saccharin solution (0.2%) than did controls. When offered ad libitum access to granular sucrose and lab chow vagotomized rats did not differ from controls in their sucrose intake, chow intake, or total caloric intake. With a 20% sucrose solution and chow available, however, the vagotomized rats consumed significantly less sucrose and total calories than did the controls. Also, unlike the controls, the vagotomized rats did not consume more of the liquid sucrose than of the granular sucrose, and failed to gain weight on the sucrose diets. When maintained on solid macronutrient diets the vagotomized rats were similar to controls in their selection of the fat, carbohydrate and protein diets. The results demonstrate that vagotomy selectively inhibits the intake of sugar solutions and not high-carbohydrate diets in general. Possible explanations for this effect are discussed.