Lateral Hypothalamic Lesions

Address all correspondence to Dr. George A. Bray. Received for publication 14 February 1983 and in revised form 19 May 1983. INTRODUCTION Following the observation by Hetherington and Ranson (1) that ventromedial hypothalamic lesions were associated with obesity, Anand and Brobeck (2) demonstrated in 1951 that lesions placed more laterally in the hypothalamus were associated with hypophagia or aphagia. These observations led to the dual center hypothesis for the control of food intake (3) and to numerous studies on the functional aspects of the lateral hypothalamic (LH)l syndrome (4-6). In animals with LH injury, there is loss of generalized attention (7). If animals during this early phase are provided adequate food intake and liquid, they will gradually recover many of their functions, but do not recover their sensitivity to food intake during insulin-induced hypoglycemia (8). Recent studies have demonstrated that lesions in the lateral hypothalamus are associated with gastric ulcers (9, 10). In addition, there is an increase in overall metabolism, which persists for at least 3 mo after LH lesions (11) and is manifested as an increase in oxygen consumption within hours after the LH lesion (12-14). There is also a persistent elevation in core temperature following LH lesions (15). These latter observations raised the possibility that the sympathetic nervous system might play a role in the regulation of body weight and metabolism in rats with LH lesions. We have investigated this hypothesis in the LH-lesioned rat by measuring the norepinephrine (NE) turnover in peripheral tissue in both the acute and chronic phases following LH lesions. 'Abbreviations used in this paper: a-MPT, a-methyl-ptyrosine; BAT, brown adipose tissue; IBAT, interscapular BAT; LH, lateral hypothalamic (lesion, syndrome); NE, norepinephrine; PVH lesion, paraventricular hypothalamic lesion. J. Cliin. Invest. The American Society for Clinical Investigation, Inc. * 0021-9738/83/09/0919/09 $1.00 Volume 72 September 1983 919-927 919