Brown (BAT) and white (WAT) adipose tissue in high-fat junk food (HFJF) and chow-fed rats with dorsomedial hypothalamic lesions (DMNL rats).
Male weanling rats received dorsomedial hypothalamic nucleus lesions (DMNL) or sham operations and were fed for 173 postoperative days a high-fat diet and given a 32% sucrose solution as drinking fluid. This was supplemented with chocolate chip cookies, potato chips and marshmallows. Other DMNL and sham-operated controls were fed lab chow instead of the above high-fat junk food diet (HFJF) and given tap water instead of 32% sucrose solution. All animals were killed on postoperative day 174. Caloric intake per 100 g body weight was similar in all groups; however, the HFJF fed control and DMNL rats had significantly elevated carcass fat. Since HFJF-DMNL rats were not nearly as obese as the HFJF control animals, it appears that the DMNL offered some protection against the HFJF-diet-produced obesity. When their smaller body size is considered. DMN lesions had no effect on brown adipose tissue (BAT) mass in chow-fed or HFJF fed rats, whereas BAT size was significantly enlarged in HFJF-fed control animals. This suggests but does not prove that HFJF-fed controls, but not DMNL rats, may be using dietary-induced thermogenesis (DIT) to attenuate their obesity. We hypothesize that the HFJF-fed DMNL may not be enhancing DIT as reflected in normal BAT size, because they had not attained a degree of fatness to activate this system, or the DMN lesions impaired its activation. Both HFJF-fed groups showed reduced linear growth compared to their counterparts. The reason for stunting is uncertain, but may be related to their low plasma insulin concentrations.
Bernardis
L L
LL
Neurovisceral Research Laboratory, Veterans Administration Medical Center Buffalo, NY.
Bellinger
L L
LL
D000273:Adipose Tissue / Q000502:physiology*; D002001:Adipose Tissue, Brown / Q000502:physiology*; D000818:Animals; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology*; D001931:Brain Mapping; D004302:Dorsomedial Hypothalamic Nucleus / Q000502:physiology*; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005518:Food Preferences / Q000502:physiology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains