Experimental Hypothalamic Hyperphagia in the Albino Rat *

Experimental study of hypothalamic obesity is based upon a foundation laid by clinicians who described lesions of the hypophysiohypothalamic region in obese human patients. Because of the non-specific character of the lesions which they found, previous investigation was naturally directed toward discovering whether damage to the hypothalamus, to the hypophysis, or to both was necessary to produce this condition. A brief review of the data which established the hypothalamic etiology follows. Hypothalamic obesity was first described by Mohr42 in a 5 7-yearold woman who became remarkably obese within the year before her death. At autopsy there was found a hypophysial tumor large enough to deform the sella and to distort and compress the base of the brain, including the cerebral peduncles, optic nerves and chiasma, and the region of the hypothalamus. No attempt was made to explain the excessive deposition of fat nor to distinguish between the hypophysial and the hypothalamic injury. By the time of publication of Fr6hlich's paper20 in 1901, nine similar reports had already appeared. Frohlich considered the essential symptoms of the disease to be adiposity and genital underdevelopment caused by pituitary involvement that failed to produce acromegaly. His theory of the hypophysial origin of the condition, although now completely discredited, was supported by the experimental study of Crowe, Cushing, and Homans,"3 Bell,3 and Dott.15 Three years later, Erdheim,17 in 1904, questioned the validity of Frohlich's theory, pointing out that in certain cases of this type of obesity the hypophysis had been found to be relatively undamaged, that no particular type of tumor had been found responsible, and