title: Leptin downregulates ghrelin levels in streptozotocin-induced diabetic mice.
abstract: Ghrelin, an orexigenic peptide produced in the stomach, is increased in streptozotocin (STZ)-induced diabetic (DM) mice. This study clarifies the regulation of ghrelin levels by leptin in STZ-DM mice. STZ-DM mice had higher plasma ghrelin concentrations and greater ghrelin mRNA expression than control mice. Changes in ghrelin levels were dose dependently attenuated by the subcutaneous injection of leptin (0-27 nmol x kg(-1) x day(-1) over 7 days). Leptin treatment also partially reversed the hyperphagia and hyperglycemia observed in STZ-DM mice, but not the hypoinsulinemia, and there was a decrease in plasma ghrelin concentrations and ghrelin mRNA levels compared with STZ-LEP pair-fed mice. These results indicate that leptin treatment partially reverses elevated plasma ghrelin levels in STZ-DM mice independent of food intake and insulin, and suggest that hypoleptinemia in STZ-DM mice upregulates ghrelin.
authors.affiliation: Dept. of Internal Medicine 1, Faculty of Medicine, Oita University, 1-1 Idaigaoka,Hasama, Oita, 879-5593 Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Tsubone
authors.forename: Takayuki
authors.initials: T
authors.lastname: Masaki
authors.forename: Isao
authors.initials: I
authors.lastname: Katsuragi
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kakuma
authors.forename: Hironobu
authors.initials: H
authors.lastname: Yoshimatsu
mesh_terms: D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects; D054439:Ghrelin; D007279:Injections, Subcutaneous; D020738:Leptin / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D036361:Peptide Hormones / Q000097:blood*; D013311:Streptozocin
chemical_list: D054439:Ghrelin; D020738:Leptin; D036361:Peptide Hormones; D013311:Streptozocin