Document Detail


Brief hyperglycaemia in the early pregnant rat increases fetal weight at term by stimulating placental growth and affecting placental nutrient transport.
MedLine Citation:
PMID:  17430988     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
In pregnant women with type 1 diabetes, suboptimal glucose control in the first trimester is a strong predictor for giving birth to a large fetus. However, the mechanisms underlying this association are unknown. We hypothesized that transient hyperglycaemia in early pregnancy results in (1) increased placental growth and (2) an up-regulation of placental nutrient transport capacity, which leads to fetal overgrowth at term. In order to test this hypothesis, pregnant rats were given intraperitoneal injections of glucose (2 g kg(-1), resulting in a 50-100% increase in blood glucose level during 90 min) or saline (control) in either early or late gestation using four different protocols: one single injection on gestational day (GD) 10 (n=5), three injections on GD 10 (n=8-9), six injections on GD 10 and 11 (n=9-11) or three injections on GD 19 (n=7-8). Multiple injections were given approximately 4 h apart. Subsequently, animals were studied on GD 21. Three glucose injections in early pregnancy significantly increased placental weight by 10%, whereas fetal weight was found to be increased at term in response to both three (9% increase in fetal weight, P<0.05) and six glucose injections (7%, P=0.05) in early gestation. A single glucose injection on GD 10 or three injections of glucose on GD 19 had no effect on placental or fetal growth. In groups where a change in feto-placental growth was observed, we measured placental system A and glucose transport activity in the awake animals on GD 21 and placental expression of the glucose and amino acid transporters GLUT1, GLUT3, SNAT2 (system A), LAT1 and LAT 2 (system L). Placental system A transport at term was down-regulated by six glucose injections in early pregnancy (by -33%, P<0.05), whereas placental mRNA and protein levels were unchanged. No long-term alterations in maternal metabolic status were detected. In conclusion, we demonstrate that transient hyperglycaemia in early pregnancy is sufficient to increase fetal weight close to term. In contrast, brief hyperglycaemia in late pregnancy did not stimulate fetal growth. Increased fetal growth may be explained by a larger placenta, which would allow for more nutrients to be transferred to the fetus. These data suggest that maternal metabolic control in early pregnancy is an important determinant for feto-placental growth and placental function throughout the remainder of gestation. We speculate that maternal metabolism in early pregnancy represents a key environmental cue to which the placenta responds in order to match fetal growth rate with the available resources of the mother.
Authors:
Anette Ericsson; Karin Säljö; Eleonor Sjöstrand; Nina Jansson; Puttur D Prasad; Theresa L Powell; Thomas Jansson
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2007-04-12
Journal Detail:
Title:  The Journal of physiology     Volume:  581     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  2007 Jun 
Date Detail:
Created Date:  2007-06-15     Completed Date:  2007-08-09     Revised Date:  2013-06-06    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  1323-32     Citation Subset:  IM    
Affiliation:
Perinatal Center, Institute of Neuroscience and Physiology, Gothenburg University, Box 432, s-405 30 Gothenburg, Sweden. anette.ericsson@fysiologi.gu.se
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MeSH Terms
Descriptor/Qualifier:
Amino Acid Transport System y+ / metabolism
Amino Acid Transport Systems / metabolism
Amino Acid Transport Systems, Neutral / genetics,  metabolism*
Animals
Antigens, CD98 Light Chains / metabolism
Blood Glucose / metabolism
Diabetes, Gestational / blood,  chemically induced,  metabolism*,  pathology
Disease Models, Animal
Female
Fetal Nutrition Disorders / blood,  etiology*,  metabolism,  pathology
Fetal Weight*
Gestational Age
Glucose
Glucose Transport Proteins, Facilitative / genetics,  metabolism*
Glucose Transporter Type 1 / metabolism
Glucose Transporter Type 3 / metabolism
Hyperglycemia / blood,  chemically induced,  complications,  metabolism*,  pathology
Insulin / blood
Large Neutral Amino Acid-Transporter 1 / metabolism
Maternal-Fetal Exchange*
Organ Size
Placenta / metabolism*,  pathology
Pregnancy
RNA, Messenger / metabolism
Rats
Rats, Sprague-Dawley
Chemical
Reg. No./Substance:
0/Amino Acid Transport System y+; 0/Amino Acid Transport Systems; 0/Amino Acid Transport Systems, Neutral; 0/Antigens, CD98 Light Chains; 0/Blood Glucose; 0/Glucose Transport Proteins, Facilitative; 0/Glucose Transporter Type 1; 0/Glucose Transporter Type 3; 0/Insulin; 0/Large Neutral Amino Acid-Transporter 1; 0/RNA, Messenger; 0/SNAT2 protein, rat; 0/Slc2a1 protein, rat; 0/Slc2a3 protein, rat; 0/Slc7a8 protein, rat; 50-99-7/Glucose
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