METABOLIC EFFECTS OF HYPERPHAGIA IN THE HYPOTHALAMIC-HYPERPHAGIC RAT

Abstract

Metabolic effects of hyperphagia have been investigated in male rats in which hyperphagia was induced by bilateral, electrolytic lesions in the region of the ventromedial nuclei of the hypothalamus. In the early dynamic phase of hyperphagia, it would appear that increased body weight gain is a direct effect of increased energy intake not balanced by the observed increased spontaneous activity. In these animals increased lipogenesis ( 14 C-acetate and 14 C-glucose) and decreased lipolysis in vitro were evident with no evidence of altered thyroid function. Further, as determined by 35 S incorporation in costal cartilage, the hyperphagia did not elicit an increased rate of skeletal growth. In the static phase, spontaneous activity was not increased, metabolic patterns were significantly altered in the direction of increased lipogenesis and decreased lipolysis, and there appeared to be a decreased uptake and release of 131 I by the thyroid, which is suggestive of thyroid hypofunction.