Comportement alimentaire et variations métaboliques chez les rats hyperphagiques nourris en alimentation séparée

Abstract

In our protocol of separate feeding, the rat spent one hr ingesting one g of casein, then he was allowed to ad lib a protein free diet during the remaining 23 hr. When the ventro-medial nucleus of the hypothalamus was destroyed in these rats, they no longer adjusted their energy intake according to protein meal ingested. If they were fed with either a mixed diet (10 per cent casein) or with separate meals, the lesioned animals had a hyperphagic behavior which was almost identical. In 4 weeks they doubled their weight and the increase in weight followed the consummation. After which the hyperphagia regressed, the weight stabilized, the animals being at the threshold of the static phase of obesity. The biochemical tests showed then a rise in the metabolic activity of the liver which can be observed by an increase of proteins, of RNA, of glycogen and of lipids. Also, one noticed a very important increase in the percentage of glycogen in the muscle. Furthermore, all the operated animals showed an increase in the amount of corticosterone in the plasma, also of the total quantity of the hormone present in the adrenal glands. This state of hypercorticism could explain the variations observed in both the liver and the muscle.