title: Thermogenesis following meal feeding, isoproterenol, and cold in rats with LH lesions.
abstract: Responses to several thermogenic stimuli were measured in rats maintaining stable but reduced body weights following lateral hypothalamic (LH) lesions. Oxygen consumption was monitored in open-circuit respirometers before and after exposure to cold (16.5 degrees C), intubation of a meal, and isoproterenol injection (40 micrograms/kg 0.75). Observations were made in both warm- (28 degrees C) and cold-acclimated (9 degrees C) LH-lesioned rats. Cold exposure, intubation, and drug injection each caused marked increases in heat production in sham- and LH-lesioned rats. This thermogenic response was similar in magnitude and form for both groups. Acclimation to 9 degrees C caused increased baseline levels of heat production when measured at 28 degrees C. Subsequent exposure to thermogenic stimuli revealed an exaggerated response to isoproterenol but not intubation in cold-acclimated groups. The LH-lesioned cold-acclimated rats responded in the same manner as sham-lesioned cold-acclimated rats. These findings are in contrast to the immediate postlesion period when rats show enhanced thermogenic activity. At reduced body weights LH-lesioned rats show normal rates of heat production and make normal responses to thermogenic stimuli. Enhanced thermogenesis does not appear to play a role in the maintenance of chronically reduced body mass in LH-lesioned rats.
authors.affiliation: Department of Psychology, University of Wisconsin, Madison 53706.
authors.forename: S W
authors.initials: SW
authors.lastname: Corbett
authors.forename: B
authors.initials: B
authors.lastname: Roland
authors.forename: R E
authors.initials: RE
authors.lastname: Keesey
mesh_terms: D000064:Acclimatization; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D003080:Cold Temperature; D004435:Eating; D007026:Hypothalamic Area, Lateral / Q000502:physiology*; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
chemical_list: D007545:Isoproterenol