title: Intracerebroventricular interleukin-6 treatment decreases body fat in rats.
abstract: Recently we found that interleukin-6 (IL-6) knockout mice develop mature-onset obesity and that a single intracerebroventricular (ICV) injection of IL-6 increases energy expenditure. In the present study we investigated if chronic ICV treatment with IL-6 can suppress body fat mass. IL-6 was injected ICV daily for two weeks to rats fed a high-fat diet. IL-6 treatment but not saline treatment decreased body weight by 8.4% and decreased the relative weights of mesenteric and retroperitoneal fat pads. Consistent with this, circulating leptin levels were decreased by 40% after IL-6 treatment but not after saline treatment. Average food intake per day was decreased in the IL-6 treated group compared to the saline treated rats. IL-6 treatment did not change hepatic expression of the acute-phase protein haptoglobin, serum levels of insulin or insulin-like growth factor-I, or the weights of the heart, liver, kidneys, adrenals, and spleen. We conclude that centrally administered IL-6 can decrease body fat in rats without causing acute-phase reaction.
authors.affiliation: Research Centre for Endocrinology and Metabolism, Sahlgrenska University Hospital, Göteborg, Sweden. Kristina.wallenius@medic.gu.se
authors.forename: Kristina
authors.initials: K
authors.lastname: Wallenius
authors.forename: Ville
authors.initials: V
authors.lastname: Wallenius
authors.forename: David
authors.initials: D
authors.lastname: Sunter
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Dickson
authors.forename: John-Olov
authors.initials: JO
authors.lastname: Jansson
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects*; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002149:Energy Intake; D006242:Haptoglobins / Q000378:metabolism; D007276:Injections, Intraventricular; D015850:Interleukin-6 / Q000008:administration & dosage / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009765:Obesity / Q000517:prevention & control*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
chemical_list: D006242:Haptoglobins; D015850:Interleukin-6