Method of leptin dosing, strain, and group housing influence leptin sensitivity in high-fat-fed weanling mice.
High-fat diets are reported to induce resistance to peripherally administered leptin. In an attempt to develop a model of juvenile diet-induced obesity, mice were weaned onto high-fat diet. Male and female, 35-day-old, C57BL/6J high-fat (45% kcal fat) diet-fed mice housed individually on grid floors did not decrease food intake or body weight in response to intraperitoneal (30 microg), lateral ventricle (5 microg), or third ventricle (0.5 microg) injections of leptin. Body weight and fat were significantly reduced by 13-day intraperitoneal infusions of 10 microg leptin/day, which doubled circulating leptin. Leptin infusion also reduced body fat in weanling, high-fat diet-fed NIH Swiss mice. Group housing mice on bedding prevented loss of fat in high-fat diet-fed male and female NIH Swiss and female C57BL/6J mice. These results indicate that peripherally infused leptin reduces fat in part by increasing thermogenesis and that inhibition of food intake in high-fat diet-fed mice requires either chronic activation of central leptin receptors or is independent of receptors that inhibit feeding in response to an acute central injection of leptin.
Bowen
Heather
H
Department of Foods and Nutrition, University of Georgia, Athens, Georgia 30602, USA.
Mitchell
Tiffany D
TD
Harris
Ruth B S
RB
D000818:Animals; D001823:Body Composition / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D004041:Dietary Fats / Q000494:pharmacology*; D004333:Drug Administration Routes; D004351:Drug Resistance; D002149:Energy Intake / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D006799:Housing, Animal; D020738:Leptin / Q000008:administration & dosage* / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009929:Organ Size / Q000187:drug effects; D013045:Species Specificity; D014886:Weaning
D004041:Dietary Fats; D020738:Leptin