Chonically reduced body weight in rats sustaining lesions of the lateral hypothalamus and maintained on palatable diets and drinking solutions.

Abstract

Male rats sustaining lateral hypothalamic (LH) lesions regulated their body weight at a reduced level when maintained for 1 mo. postlesion upon a wet mash diet. Thereafter, for a period of 84 days, half of these animals were offered a high fat dies whereas the remaining animals continued to receive wet mash. A series of palatable drinking solutions were also offered. Body weight remained at reduced levels relative to intact control animals regardless of the diet offered, even under conditions of high fluid intake generated by the palatable drinking solutions. These results contradict the interpretation of Mufson and Wampler that the lower body weight observed in LH-lesioned animals is secondary to lesion-produced "finickiness" and/or dehydration resulting from hypodipsia. Rather, a primary shift in the set point for body weight appears to underlie the reduced levels of weight maintenance in LH-lesioned animals.