title: Effect of metformin on adipose tissue resistin expression in db/db mice.
abstract: Resistin, a novel adipose-derived protein, has been proposed to cause insulin-resistant states in obesity. To evaluate whether an insulin-sensitizing drug, metformin, regulates adipose tissue resistin expression, murine models of obesity and diabetes, db/db mice, were treated with metformin (metformin group), insulin (insulin group), and vehicle (control group) for 4 weeks, followed by analyzing resistin protein expression in their adipose tissues. Unexpectedly, resistin protein expression was increased by 66% in the metformin group relative to the control group, while it did not differ between the insulin and control groups. Hyperinsulinemia was improved in the metformin group, while the insulin group exhibited severe hyperinsulinemia, similar to the control group. Furthermore, in comparison between obese mice (db/db mice) and age-matched lean controls, resistin protein expression was reduced by 58% in the obese mice with severe hyperinsulinemia. These data collectively suggest that resistin expression may be suppressed by hyperinsulinemia and that metformin may upregulate resistin expression via the improvement of hyperinsulinemia in obesity.
authors.affiliation: Department of Geriatric Medicine, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan. fujitah@med.akita-u.ac.jp
authors.forename: Hiroki
authors.initials: H
authors.lastname: Fujita
authors.forename: Hiromi
authors.initials: H
authors.lastname: Fujishima
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Morii
authors.forename: Jun
authors.initials: J
authors.lastname: Koshimura
authors.forename: Takuma
authors.initials: T
authors.lastname: Narita
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kakei
authors.forename: Seiki
authors.initials: S
authors.lastname: Ito
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D006729:Hormones, Ectopic / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D036341:Intercellular Signaling Peptides and Proteins; D008687:Metformin / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D020932:Nerve Growth Factor; D011506:Proteins; D052243:Resistin
chemical_list: D006729:Hormones, Ectopic; D007004:Hypoglycemic Agents; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; D052243:Resistin; C499623:Retn protein, mouse; C413576:Retnla protein, mouse; D020932:Nerve Growth Factor; D008687:Metformin