Document Detail

System A activity and vascular function in the placental-specific Igf2 knockout mouse.
MedLine Citation:
PMID:  21851977     Owner:  NLM     Status:  MEDLINE    
OBJECTIVES: Deletion of the placental-specific P0 transcript of the insulin-like growth factor gene (Igf2) reduces placental growth from early pregnancy onwards. In Igf2 P0 knockout fetuses (P0), maternofetal flux of (14)C-methylaminoisobutyric acid ((14)C-MeAIB) mediated by system A amino acid transporter activity is increased at embryonic day 16 (E16), but this stimulation is not sustained, and by E19, fetal growth restriction (FGR) ensues. Here, we investigated whether upregulated (14)C-MeAIB transfer does occur concomitantly with a change in System A amino acid transporter activity and whether altered uteroplacental vascular function contributes to the FGR. We tested the hypothesis that FGR in P0 mice is attributable to altered nutrient transport rather than aberrant uteroplacental vascular function.
METHODS: Plasma membrane vesicles were isolated from placentas of P0 and wild-type (WT) fetuses at E16 and E19. System A amino acid transporter activity was measured as sodium-dependent (14)C-MeAIB uptake over 60s. Wire myography was performed on uterine artery branches supplying P0 or WT implantation sites and agonist-induced constriction and dilation measured.
RESULTS: Sodium-dependent uptake of (14)C-MeAIB (at 60s) was significantly (P < 0.05) higher in P0 compared to WT vesicles at E16; at E19 (14)C-MeAIB uptake was similar between P0 and WT. Uterine artery branch vascular reactivity was comparable between groups.
CONCLUSIONS: System A activity in the maternal-facing plasma membrane of syncytiotrophoblast layer II underpins the adaptations observed in the transplacental MeAIB flux of P0 mice. Unaltered uterine artery vascular function suggests that the FGR phenotype of P0 fetuses is primarily due to deficient placental nutrient exchange capacity.
L C Kusinski; M R Dilworth; P N Baker; C P Sibley; M Wareing; J D Glazier
Related Documents :
22028857 - Changes in cardiac substrate transporters and metabolic proteins mirror the metabolic s...
14522437 - Pharmacological effect and toxicity of alkaloids from gelsemium elegans benth.
11945157 - Fatty acid amide hydrolase, an enzyme with many bioactive substrates. possible therapeu...
12061397 - A review on usnic acid, an interesting natural compound.
15315407 - Brønsted acid-promoted cyclizations of siloxyalkynes with arenes and alkenes.
17107007 - Infrared spectroscopic studies of siderophore-related hydroxamic acid ligands adsorbed ...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2011-08-17
Journal Detail:
Title:  Placenta     Volume:  32     ISSN:  1532-3102     ISO Abbreviation:  Placenta     Publication Date:  2011 Nov 
Date Detail:
Created Date:  2011-11-07     Completed Date:  2012-03-06     Revised Date:  2014-02-20    
Medline Journal Info:
Nlm Unique ID:  8006349     Medline TA:  Placenta     Country:  England    
Other Details:
Languages:  eng     Pagination:  871-6     Citation Subset:  IM    
Copyright Information:
Copyright © 2011 Elsevier Ltd. All rights reserved.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Amino Acid Transport System A / metabolism*,  physiology
Biological Transport
Blood Vessels / metabolism,  physiology*
Cell Fractionation
Insulin-Like Growth Factor II / genetics*,  metabolism
Mice, Inbred C57BL
Mice, Knockout
Organ Specificity / genetics
Placenta / blood supply,  metabolism*
Placental Circulation / genetics,  physiology
Uterine Artery / metabolism,  physiology
beta-Alanine / analogs & derivatives,  pharmacokinetics
Grant Support
92495//Medical Research Council; G0802770//Medical Research Council; //Biotechnology and Biological Sciences Research Council
Reg. No./Substance:
0/Amino Acid Transport System A; 0/IGF2 protein, mouse; 11P2JDE17B/beta-Alanine; 19036-43-2/2,2-dimethyl-beta-alanine; 67763-97-7/Insulin-Like Growth Factor II

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Comparative efficacy and acceptability of antimanic drugs in acute mania: a multiple-treatments meta...
Next Document:  Diagnostic testing, treatment, cost of care, and survival among registered and non-registered patien...