Effect of amino acids and protein on foot intake of hyperphagic and recovered aphagic rats.

SCHARRER, ERWIN, CLIFTON A. BAILE, AND JEAN MAYER. Effect of amino acids and protein on food intake of hyperphagic and recovered aphagic rats. Am. J. Physiol. 218(Z): 400-404. 1970.Food intake of normal, recovered hypothalamic aphagic, and hypothalamic hyperphagic rats as affected by excessive dietary leucine, amino acid imbalance, and high level of dietary protein was investigated. In normals and recovered aphagics food intake was depressed to similar levels by all experimental diets. Under the same conditions hyperphagics generally reduced their food intake even more than normals. T.his greater decrease may in part be due to an increased sensitivity to palatability. From these findings, it is concluded that the central nervous system structures instrumental in these food-intake depressions are still intact in rats with hypothalamic hyperphagia, and in rats having recovered from hypothalamic aphagia. In contrast to recovered aphagics, normals became transiently hyperphagic after the diet with excessive leucine was replaced by the control diet. Apparently this type of hyperphagia is one of the mechanisms of body-weight regulation, since body weight had decreased markedly while the leucine diet was fed. It is concluded that this mechanism is damaged in rats with lesions in the lateral hypothalamic areas.