PMID- 17430988 OWN - NLM STAT- MEDLINE DCOM- 20070809 LR - 20201209 IS - 0022-3751 (Print) IS - 1469-7793 (Electronic) IS - 0022-3751 (Linking) VI - 581 IP - Pt 3 DP - 2007 Jun 15 TI - Brief hyperglycaemia in the early pregnant rat increases fetal weight at term by stimulating placental growth and affecting placental nutrient transport. PG - 1323-32 AB - 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. FAU - Ericsson, Anette AU - Ericsson A AD - Perinatal Center, Institute of Neuroscience and Physiology, Gothenburg University, Box 432, s-405 30 Gothenburg, Sweden. anette.ericsson@fysiologi.gu.se FAU - Saljo, Karin AU - Saljo K FAU - Sjostrand, Eleonor AU - Sjostrand E FAU - Jansson, Nina AU - Jansson N FAU - Prasad, Puttur D AU - Prasad PD FAU - Powell, Theresa L AU - Powell TL FAU - Jansson, Thomas AU - Jansson T LA - eng PT - Comparative Study PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20070412 PL - England TA - J Physiol JT - The Journal of physiology JID - 0266262 RN - 0 (Amino Acid Transport System A) RN - 0 (Amino Acid Transport System y+) RN - 0 (Amino Acid Transport Systems) RN - 0 (Amino Acid Transport Systems, Neutral) RN - 0 (Blood Glucose) RN - 0 (Fusion Regulatory Protein 1, Light Chains) RN - 0 (Glucose Transport Proteins, Facilitative) RN - 0 (Glucose Transporter Type 1) RN - 0 (Glucose Transporter Type 3) RN - 0 (Insulin) RN - 0 (Large Neutral Amino Acid-Transporter 1) RN - 0 (RNA, Messenger) RN - 0 (Slc2a1 protein, rat) RN - 0 (Slc2a3 protein, rat) RN - 0 (Slc38a2 protein, rat) RN - 0 (Slc7a8 protein, rat) RN - IY9XDZ35W2 (Glucose) SB - IM MH - Amino Acid Transport System A MH - Amino Acid Transport System y+/metabolism MH - Amino Acid Transport Systems/metabolism MH - Amino Acid Transport Systems, Neutral/genetics/*metabolism MH - Animals MH - Blood Glucose/metabolism MH - Diabetes, Gestational/blood/chemically induced/*metabolism/pathology MH - Disease Models, Animal MH - Female MH - Fetal Nutrition Disorders/blood/*etiology/metabolism/pathology MH - *Fetal Weight MH - Fusion Regulatory Protein 1, Light Chains/metabolism MH - Gestational Age MH - Glucose MH - Glucose Transport Proteins, Facilitative/genetics/*metabolism MH - Glucose Transporter Type 1/metabolism MH - Glucose Transporter Type 3/metabolism MH - Hyperglycemia/blood/chemically induced/complications/*metabolism/pathology MH - Insulin/blood MH - Large Neutral Amino Acid-Transporter 1/metabolism MH - *Maternal-Fetal Exchange MH - Organ Size MH - Placenta/*metabolism/pathology MH - Pregnancy MH - RNA, Messenger/metabolism MH - Rats MH - Rats, Sprague-Dawley PMC - PMC2170823 EDAT- 2007/04/14 09:00 MHDA- 2007/08/10 09:00 PMCR- 2008/06/15 CRDT- 2007/04/14 09:00 PHST- 2007/04/14 09:00 [pubmed] PHST- 2007/08/10 09:00 [medline] PHST- 2007/04/14 09:00 [entrez] PHST- 2008/06/15 00:00 [pmc-release] AID - jphysiol.2007.131185 [pii] AID - 10.1113/jphysiol.2007.131185 [doi] PST - ppublish SO - J Physiol. 2007 Jun 15;581(Pt 3):1323-32. doi: 10.1113/jphysiol.2007.131185. Epub 2007 Apr 12.