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Maternal insulin-like growth factor-II promotes placental functional development via the type 2 IGF receptor in the guinea pig
journal contribution
posted on 2008-04-01, 00:00 authored by A N Sferruzzi-Perri, Julie OwensJulie Owens, P Standen, C T RobertsIn guinea pigs, maternal insulin-like growth factor (IGF) infusion in early-pregnancy enhances placental transport near-term, increasing fetal growth and survival. The effects of IGF-II, but not IGF-I, appear due to enhanced placental labyrinthine (exchange) development. To determine if the type-2 IGF receptor (IGF2R) mediates these distinct actions of exogenous IGF-II in the mother, we compared the impact of IGF-II with an IGF-II analogue, Leu(27)-IGF-II, which only binds the IGF2R. IGF-II, Leu(27)-IGF-II (1mg/kg per day.sc) or vehicle were infused from days 20-38 of pregnancy (term = 67 days) and placental structure and uptake and transfer of [(3)H]-methyl-D-glucose (MG) and [(14)C]-amino-isobutyric acid (AIB) and fetal growth and plasma metabolites, were measured on day 62. Both IGF-II and Leu(27)-IGF-II increased the volume of placental labyrinth, trophoblast and maternal blood space within the labyrinth and total surface area of trophoblast for exchange, compared to vehicle. Leu(27)-IGF-II also reduced the barrier to diffusion (trophoblast thickness) compared to vehicle and IGF-II. Both IGF-II and Leu(27)-IGF-II increased fetal plasma amino acid concentrations and placental transfer of MG to the fetus compared to vehicle, with Leu(27)-IGF-II also increasing AIB transport compared with vehicle and IGF-II. In addition, Leu(27)-IGF-II increased fetal weight compared to vehicle. In conclusion, maternal treatment with IGF-II or Leu(27)-IGF-II in early gestation, induce similar placental and fetal outcomes near term. This suggests that maternal IGF-II in early gestation acts in part via the IGF2R to persistently enhance placental functional development and nutrient delivery and promote fetal growth.
History
Journal
PlacentaVolume
29Issue
4Pagination
347 - 355Publisher
ElsevierLocation
Amsterdam, The NetherlandsPublisher DOI
ISSN
0143-4004Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
2008, Elsevier Ltd.Usage metrics
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3-O-MethylglucoseAdipose TissueAmino AcidsAminoisobutyric AcidsAnimalsBiological TransportBlood VesselsBody CompositionBody WeightFemaleFetal WeightFetusGuinea PigsInsulin-Like Growth Factor IILitter SizeMaternal-Fetal ExchangeOrgan SizePlacentaPlacentationPregnancyReceptor, IGF Type 2TrophoblastsScience & TechnologyLife Sciences & BiomedicineDevelopmental BiologyObstetrics & GynecologyReproductive Biologyinsulin-like growth factortype-2 IGF receptorMANNOSE 6-PHOSPHATE RECEPTORBINDING-PROTEINSRHABDOMYOSARCOMA CELLSFOOD RESTRICTIONFACTOR (IGF)-IMOUSETROPHOBLASTEXPRESSIONMIGRATION
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