title: Leptin alters the structural and functional characteristics of adipose tissue before birth.
abstract: This study aimed to determine for the first time whether leptin can act to alter the structural and functional characteristics of adipose tissue before birth. Leptin (0.48 mg/kg/day) or saline was infused intravenously into fetal sheep for 4 days from either 136 or 137 days of gestation (term=147+/-3 days). Circulating leptin concentrations were increased approximately four- to fivefold by leptin infusion. Leptin infusion resulted in a significant increase in the proportion of smaller lipid locules present within fetal perirenal adipose tissue (PAT), and this was associated with a significant increase in the proportion of multilocular tissue and a significant decrease in the proportion and relative mass of unilocular tissue in fetal PAT. The relative abundance of leptin mRNA in fetal PAT was significantly lower in the leptin-infused group, and there was a positive correlation between the relative abundance of leptin mRNA and the proportion of unilocular adipose tissue in fetal PAT. The amount of uncoupling protein 1 tended to be higher (P=0.06) in leptin-infused compared with saline-infused fetuses. This is the first demonstration that leptin can act to regulate the lipid storage characteristics, leptin synthetic capacity, and potential thermogenic functions of fat before birth.
authors.affiliation: Department of Physiology, Adelaide University, SA 5005, Australia.
authors.forename: B S J
authors.initials: BS
authors.lastname: Yuen
authors.forename: P C
authors.initials: PC
authors.lastname: Owens
authors.forename: B S
authors.initials: BS
authors.lastname: Muhlhausler
authors.forename: C T
authors.initials: CT
authors.lastname: Roberts
authors.forename: M E
authors.initials: ME
authors.lastname: Symonds
authors.forename: D H
authors.initials: DH
authors.lastname: Keisler
authors.forename: J R
authors.initials: JR
authors.lastname: McFarlane
authors.forename: K G
authors.initials: KG
authors.lastname: Kauter
authors.forename: Y
authors.initials: Y
authors.lastname: Evens
authors.forename: I C
authors.initials: IC
authors.lastname: McMillen
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology* / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis; D005333:Fetus / Q000033:anatomy & histology* / Q000187:drug effects / Q000378:metabolism*; D007473:Ion Channels; D020738:Leptin / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology* / Q000502:physiology; D050356:Lipid Metabolism; D008565:Membrane Proteins / Q000096:biosynthesis; D024101:Mitochondrial Proteins; D008954:Models, Biological; D012333:RNA, Messenger / Q000096:biosynthesis; D012756:Sheep; D000071256:Uncoupling Protein 1
chemical_list: D002352:Carrier Proteins; D007473:Ion Channels; D020738:Leptin; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; D000071256:Uncoupling Protein 1