The Relation Between Water Intake and Food Intake in Normal Rats and in Rats with Hypothalamic Hyperphagia *

The obesity described by Babinski,2 Fr'ohlich,18 and Erdheim16 in patients suffering from lesions at the base of the brain has now been produced experimentally in the dog,20 24 cat,32 monkey,9 and rat.6 8 Moreover, the long-existing controversy as to whether the primary lesion is in the hypophysis4' 12, 18 (as originally suggested by Fr'ohlich"8) or in the hypothalamus16 22, 30 (as Erdheim"6 first proposed) seems to have been settled when Hetherington21 showed that the pituitary is not involved in the development of the obesity which follows the production of discrete, bilaterally symmetrical lesions in the ventromedial hypothalamus of the rat. Hetherington and Ranson23 had previously shown that following the placing of these lesions no conspicuous changes could be detected in the pituitary. Thus far no primary disturbance in the intermediary metabolism of these animals has been discovered, since the alterations observed seem to'be the consequence of the hyperphagia rather than the result of the lesion.7' 3 Present work tends to emphasize the hypothesis that the obesity is a result of a fundamental disturbance of energy exchange.5 The mechanism of the hyperphagia is at present unknown, and, while it is possible that some metabolic disturbance may be responsible for it, -the n.ature of such a disturbance is wholly conjectural. Clinical investigators also have emphasized the importance of hyperphagia in the pathogenesis of human obesity."1 13, 25, 29 Since the supra-optic nucleus (lesions of which produce diabetes insipidus"7) lies just anterior to the region where the lesions are