scholarly journals Regulation of placental nutrient transport and implications for fetal growth

2002 ◽  
Vol 15 (2) ◽  
pp. 211-230 ◽  
Author(s):  
Alan W Bell ◽  
Richard A Ehrhardt
Keyword(s):  
Amino Acids ◽  
Fetal Growth ◽  
Maternal Nutrition ◽  
Nutrient Transport ◽  
Late Pregnancy ◽  
Late Gestation ◽  
Abnormal Development ◽  
Placental Transport ◽  
Specific Transport

AbstractFetal macronutrient requirements for oxidative metabolism and growth are met by placental transport of glucose, amino acids, and, to a lesser extent that varies with species, fatty acids. It is becoming possible to relate the maternal–fetal transport kinetics of these molecules in vivo to the expression and distribution of specific transporters among placental cell types and subcellular membrane fractions. This is most true for glucose transport, although apparent inconsistencies among data on the roles and relative importance of the predominant placenta glucose transporters, GLUT-1 and GLUT-3, remain to be resolved. The quantity of macronutrients transferred to the fetus from the maternal bloodstream is greatly influenced by placental metabolism, which results in net consumption of large amounts of glucose and, to a lesser extent, amino acids. The pattern of fetal nutrient supply is also altered considerably by placental conversion of glucose to lactate and, in some species, fructose, and extensive transamination of amino acids. Placental capacity for transport of glucose and amino acids increases with fetal demand as gestation advances through expansion of the exchange surface area and increased expression of specific transport molecules. In late pregnancy, transport capacity is closely related to placental size and can be modified by maternal nutrition. Preliminary evidence suggests that placental expression and function of specific transport proteins are influenced by extracellular concentrations of nutrients and endocrine factors, but, in general, the humoral regulation of placental capacity for nutrient transport is poorly understood. Consequences of normal and abnormal development of placental transport functions for fetal growth, especially during late gestation, and, possibly, for fetal programming of postnatal disorders, are discussed.

scholarly journals Placental transport in response to altered maternal nutrition

2012 ◽  
Vol 4 (2) ◽  
pp. 101-115 ◽  
Author(s):  
F. Gaccioli ◽  
S. Lager ◽  
T. L. Powell ◽  
T. Jansson
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Fetal Growth ◽  
Maternal Nutrition ◽  
Critical Role ◽  
Placental Function ◽  
Maternal Undernutrition ◽  
Placental Transport ◽  
Placental Blood ◽  
Placental Blood Flow

The mechanisms linking maternal nutrition to fetal growth and programming of adult disease remain to be fully established. We review data on changes in placental transport in response to altered maternal nutrition, including compromized utero-placental blood flow. In human intrauterine growth restriction and in most animal models involving maternal undernutrition or restricted placental blood flow, the activity of placental transporters, in particular for amino acids, is decreased in late pregnancy. The effect of maternal overnutrition on placental transport remains largely unexplored. However, some, but not all, studies in women with diabetes giving birth to large babies indicate an upregulation of placental transporters for amino acids, glucose and fatty acids. These data support the concept that the placenta responds to maternal nutritional cues by altering placental function to match fetal growth to the ability of the maternal supply line to allocate resources to the fetus. On the other hand, some findings in humans and mice suggest that placental transporters are regulated in response to fetal demand signals. These observations are consistent with the idea that fetal signals regulate placental function to compensate for changes in nutrient availability. We propose that the placenta integrates maternal and fetal nutritional cues with information from intrinsic nutrient sensors. Together, these signals regulate placental growth and nutrient transport to balance fetal demand with the ability of the mother to support pregnancy. Thus, the placenta plays a critical role in modulating maternal–fetal resource allocation, thereby affecting fetal growth and the long-term health of the offspring.

scholarly journals Regulation of Nutrient Transport across the Placenta

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Susanne Lager ◽  
Theresa L. Powell
Keyword(s):  
Cardiovascular Disease ◽  
Amino Acids ◽  
Fetal Growth ◽  
Nutrient Transport ◽  
Intervention Strategies ◽  
Regulatory Mechanisms ◽  
Nutrient Transporters ◽  
Perinatal Complications ◽  
Placental Transport ◽  
Increased Risk

Abnormal fetal growth, both growth restriction and overgrowth, is associated with perinatal complications and an increased risk of metabolic and cardiovascular disease later in life. Fetal growth is dependent on nutrient availability, which in turn is related to the capacity of the placenta to transport these nutrients. The activity of a range of nutrient transporters has been reported to be decreased in placentas of growth restricted fetuses, whereas at least some studies indicate that placental nutrient transport is upregulated in fetal overgrowth. These findings suggest that changes in placental nutrient transport may directly contribute to the development of abnormal fetal growth. Detailed information on the mechanisms by which placental nutrient transporters are regulated will therefore help us to better understand how important pregnancy complications develop and may provide a foundation for designing novel intervention strategies. In this paper we will focus on recent studies of regulatory mechanisms that modulate placental transport of amino acids, fatty acids, and glucose.

Effects of maternal nutrition during pregnancy on fetal growth and maternal constraint in sheep

2012 ◽  
Vol 52 (7) ◽  
pp. 524 ◽  
Author(s):  
C. M. C. Jenkinson ◽  
A. K. Earl ◽  
P. R. Kenyon ◽  
H. T. Blair
Keyword(s):  
Fetal Growth ◽  
Maternal Nutrition ◽  
Late Gestation ◽  
Second Trimester ◽  
Physical Constraint ◽  
Nutritional Treatment ◽  
Offspring Development ◽  
Fetal Size ◽  
Ad Libitum ◽  
Nutritional Level

This study set out to determine the stage of gestation at which maternal constraint on fetal growth occurs and whether pregnancy nutritional level could alleviate that constraint. One-hundred and thirty-eight Cheviot (C) and 114 Suffolk (S) ewes were split into two groups and bred with either 12 S or 12 C rams to generate four ewe/fetal groups CC (C dam and C sire), CSinC (crossbred fetus in C ewe), CSinS, and SS. At Day 21 of pregnancy (P21), half of the ewes in each of the four groups were randomly allocated to either a maintenance (M) or ad libitum (A) nutritional treatment, under pastoral grazing conditions. At P100, a subgroup of singleton-bearing ewes including ewes from all four groups (n = 55 in total) were euthanised (Study 1). Maternal, placental and fetal weights and sizes were recorded. The remaining ewes were fed to appetite from P140 and were allowed to lamb (n = 114 in total, Study 2) and lamb liveweights were recorded within 12 h of birth and at average days 30 and 100 (L30, L100) of lactation. In both studies, M ewes were lighter (P < 0.05) than A ewes, and CC and CSinC ewes were lighter (P < 0.05) than CSinS and SS ewes. In Study 1, maternal nutritional treatment had no effect (P > 0.05) on fetal bodyweight although fetuses from A ewes had heavier (P < 0.05) livers, spleens and thyroids than fetuses from M ewes. CC and CSinC fetuses were lighter (P < 0.01) than both CSinS and SS fetuses. In Study 2, lambs born to M ewes were lighter (P < 0.05) at birth and at L100 than lambs born to A ewes. CC lambs were lighter (P < 0.01) than CSinC, CSinS and SS lambs at birth. At L30 and L100, CC lambs were lighter (P < 0.05) than CSinC lambs, which, in turn, were lighter (P < 0.05) than both CSinS and SS lambs, which did not differ (P > 0.05). Combined, these studies indicate that maternal nutrition may have little impact on singleton-offspring development until late gestation while, in contrast, dam size affected fetal size by the end of the second trimester. These data suggest that the C ewe constrains the growth of the crossbred fetus well before a ‘physical’ constraint would be expected.

scholarly journals Maternal nutrition in early and late pregnancy in relation to placental and fetal growth

BMJ ◽  
1996 ◽  
Vol 312 (7028) ◽  
pp. 410-410 ◽  
Author(s):  
K Godfrey ◽  
S Robinson ◽  
D. Barker ◽  
C Osmond ◽  
V Cox
Keyword(s):  
Fetal Growth ◽  
Maternal Nutrition ◽  
Late Pregnancy

scholarly journals Placental Transport of Leucine, Phenylalanine, Glycine, and Proline in Intrauterine Growth-Restricted Pregnancies

2001 ◽  
Vol 86 (11) ◽  
pp. 5427-5432 ◽  
Author(s):  
Cinzia L. Paolini ◽  
Anna Maria Marconi ◽  
Stefania Ronzoni ◽  
Michela Di Noio ◽  
Paul V. Fennessey ◽  
...  
Keyword(s):  
Amino Acids ◽  
Gestational Age ◽  
Essential Amino Acids ◽  
Enrichment Ratio ◽  
Maternal Circulation ◽  
Intrauterine Growth ◽  
Fetal Blood Sampling ◽  
Placental Transport ◽  
Appropriate For Gestational Age

l-[1-13C]Leucine,[ 1-13C]glycine, l-[1-13C]phenylalanine, and l-[1-13C]proline were infused as a bolus into the maternal circulation of seven appropriate for gestational age at 30.3 ± 3.0 wk and 7 intrauterine growth-restricted pregnancies at 26.5 ± 1.0 wk gestation to investigate placental transport in vivo. Umbilical venous samples were obtained at the time of in utero fetal blood sampling at 450± 74 sec from the bolus injection. In normal pregnancies the fetal/maternal (F/M) enrichment ratios for leucine (0.76 ± 0.06) and phenylalanine (0.77 ± 0.06) were higher (P &lt; 0.01) than the F/M ratios for glycine (0.18 ± 0.04) and proline (0.22 ± 0.02). This suggests that these two essential amino acids rapidly cross the placenta in vivo. Compared with the essentials, both glycine and proline had significantly lower F/M enrichment ratios, which were not different from each other. The results support the hypothesis that amino acids with high affinity for exchange transporters cross the placenta most rapidly. In intrauterine growth-restricted pregnancies, the F/M enrichment ratio was significantly lower (P &lt; 0.01) for l-[1-13C]leucine (0.76 ± 0.06 vs. 0.48 ± 0.07) and for l-[1-13C]phenylalanine (0.77 ± 0.06 vs. 0.46 ± 0.07) compared with appropriate for gestational age pregnancies reflecting impaired transplacental flux. The F/M enrichment ratio did not differ for[ 1-13C]glycine (0.18 ± 0.04 vs. 0.17 ± 0.03), and l-[1-13C]proline (0.22 ± 0.02 vs. 0.18 ± 0.04).

An in vivo study of ovine placental transport of essential amino acids

2001 ◽  
Vol 280 (1) ◽  
pp. E31-E39 ◽  
Author(s):  
Cinzia L. Paolini ◽  
Giacomo Meschia ◽  
Paul V. Fennessey ◽  
Adrian W. Pike ◽  
Cecilia Teng ◽  
...  
Keyword(s):  
Amino Acids ◽  
Plasma Concentration ◽  
Essential Amino Acids ◽  
Maternal Plasma ◽  
Transport Systems ◽  
Fetal Plasma ◽  
Placental Transport ◽  
Rate Limiting ◽  
Pulse Flux

Under normal physiological conditions, essential amino acids (EA) are transported from mother to fetus at different rates. The mechanisms underlying these differences include the expression of several amino acid transport systems in the placenta and the regulation of EA concentrations in maternal and fetal plasma. To study the relation of EA transplacental flux to maternal plasma concentration, isotopes of EA were injected into the circulation of pregnant ewes. Measurements of concentration and molar enrichment in maternal and fetal plasma and of umbilical plasma flow were used to calculate the ratio of transplacental pulse flux to maternal concentration (clearance) for each EA. Five EA (Met, Phe, Leu, Ile, and Val) had relatively high and similar clearances and were followed, in order of decreasing clearance, by Trp, Thr, His, and Lys. The five high-clearance EA showed strong correlation ( r 2 = 0.98) between the pulse flux and maternal concentration. The study suggests that five of the nine EA have similar affinity for a rate-limiting placental transport system that mediates rapid flux from mother to fetus, and that differences in transport rates within this group of EA are determined primarily by differences in maternal plasma concentration.

scholarly journals A Review of Maternal Nutrition during Pregnancy and Impact on the Offspring through Development: Evidence from Animal Models of Over- and Undernutrition

2020 ◽  
Vol 17 (18) ◽  
pp. 6926 ◽  
Author(s):  
John F. Odhiambo ◽  
Christopher L. Pankey ◽  
Adel B. Ghnenis ◽  
Stephen P. Ford
Keyword(s):  
Fetal Growth ◽  
Growth Rates ◽  
Maternal Nutrition ◽  
University Of Wyoming ◽  
Growth Patterns ◽  
Late Gestation ◽  
Postnatal Life ◽  
Body Weights ◽  
Obesogenic Diet ◽  
And Control

Similarities in offspring phenotype due to maternal under- or over-nutrition during gestation have been observed in studies conducted at University of Wyoming. In these studies, ewes were either nutrient-restricted (NR) from early to mid-gestation, or fed an obesogenic diet (MO) from preconception through term. Offspring necropsies occurred at mid-gestation, late-gestation, and after parturition. At mid gestation, body weights of NR fetuses were ~30% lighter than controls, whereas MO fetuses were ~30% heavier than those of controls. At birth, lambs born to NR, MO, and control ewes exhibited similar weights. This was a consequence of accelerated fetal growth rates in NR ewes, and reduced fetal growth rates in MO ewes in late gestation, when compared to their respective controls. These fetal growth patterns resulted in remarkably similar effects of increased susceptibility to obesity, cardiovascular disease, and glucose intolerance in offspring programmed mostly during fetal stages of development. These data provide evidence that maternal under- and over-nutrition similarly induce the development of the same cadre of physical and metabolic problems in postnatal life.

Effect of continuous feeding on maternal protein metabolism and fetal growth in the rat

1989 ◽  
Vol 256 (6) ◽  
pp. E852-E862
Author(s):  
P. R. Ling ◽  
B. R. Bistrian ◽  
G. L. Blackburn ◽  
N. Istfan
Keyword(s):  
Fetal Growth ◽  
Muscle Protein ◽  
Late Pregnancy ◽  
Late Gestation ◽  
Physiological Importance ◽  
Maternal Contribution ◽  
Fetal Size ◽  
Continuous Feeding ◽  
Ad Libitum ◽  
Nutrient Solutions

Accelerated maternal catabolism ensures adequate fetal growth in the postabsorptive pregnant mammal during late gestation. However, the relative importance of maternal stores and diet in supplying nutrient requirements to the fetus is unknown. We have measured rates of protein synthesis and breakdown in maternal and fetal tissues during continuous intravenous feeding on days 17 and 20 in the rat, using leucine tracer infusions. Nutrient solutions supplying 180 and 250 kcal.kg-1.day-1 were tested. Changes in fetal size were measured in these rats and in rats maintained on ad libitum chow feeding. In comparison to previous results in the postabsorptive rat, leucine flux from endogenous sources into plasma was significantly suppressed, with only 12-20% of circulating leucine derived from maternal tissues. Muscle protein catabolism (previously described on day 20 of gestation) was abolished with continuous feeding. Fetal growth rate averaged 46%/day on day 17 of gestation in all groups but was reduced to 12%/day on day 20 in the rats intravenously fed 180 kcal.kg-1.day-1 and 22%/day in the rats fed 250 kcal.kg-1.day-1. Fetal growth on day 20 in the rats fed rat chow ad libitum was unaffected. We conclude that by decreasing the maternal contribution to circulating nutrients, continuous intravenous feeding may adversely affect fetal growth in late pregnancy. The findings in the current study underline the physiological importance of maternal-fetal nutrient exchange.

Progesterone secretion and fetal development during prolonged starvation in the pig.

1979 ◽  
Vol 236 (4) ◽  
pp. E335 ◽  
Author(s):  
L L Anderson ◽  
D L Hard ◽  
L P Kertiles
Keyword(s):  
Fetal Growth ◽  
Fetal Development ◽  
Maternal Nutrition ◽  
Survival Rates ◽  
Late Pregnancy ◽  
Fetal Mortality ◽  
Serum Progesterone ◽  
Prolonged Starvation ◽  
Fetal Survival ◽  
Progesterone Secretion

Roles of ovarian progesterone secretion and maternal nutrition in fetal development were investigated in a species that normally experiences considerable embryonic and fetal mortality. Pregnancies were maintained in 81% of Yorkshire pigs during prolonged starvation (e.g., 40 days; 0 kcal/day, water only) in either the middle third (days 30-70) or last third (days 70-110) of gestation compared with 100% in full-fed controls (7,028 kcal/day). In spite of severe maternal deprivation, fetal survival rates averaged 65% in starved dams and 63% in controls; mean number of living fetuses was 9.9 in starved and 9.6 in control dams. Fetal growth was reduced by maternal starvation during the middle third, but not the last third of pregnancy. Placental insufficiency was the primary cause of reduced fetal growth and resulted in abortion in a few of the dams. Progesterone in peripheral serum of dams starved either during middle or late pregnancy was maintained at levels similar (P greater than 0.05) to those in controls. Abortion occurred in starved dams only when serum progesterone concentrations dropped to less than 10 ng/ml within 3 days before loss of conceptuses.

Environmental regulation of placental phenotype: implications for fetal growth

2012 ◽  
Vol 24 (1) ◽  
pp. 80 ◽  
Author(s):  
O. R. Vaughan ◽  
A. N. Sferruzzi-Perri ◽  
P. M. Coan ◽  
A. L. Fowden
Keyword(s):  
Environmental Regulation ◽  
Fetal Growth ◽  
Molecular Mechanisms ◽  
Nutrient Transport ◽  
In Vivo Studies ◽  
Calorie Intake ◽  
Transport Capacity ◽  
Hormone Exposure

Environmental conditions during pregnancy determine birthweight, neonatal viability and adult phenotype in human and other animals. In part, these effects may be mediated by the placenta, the principal source of nutrients for fetal development. However, little is known about the environmental regulation of placental phenotype. Generally, placental weight is reduced during suboptimal conditions like maternal malnutrition or hypoxaemia but compensatory adaptations can occur in placental nutrient transport capacity to help maintain fetal growth. In vivo studies show that transplacental glucose and amino acid transfer adapt to the prevailing conditions induced by manipulating maternal calorie intake, dietary composition and hormone exposure. These adaptations are due to changes in placental morphology, metabolism and/or abundance of specific nutrient transporters. This review examines environmental programming of placental phenotype with particular emphasis on placental nutrient transport capacity and its implications for fetal growth, mainly in rodents. It also considers the systemic, cellular and molecular mechanisms involved in signalling environmental cues to the placenta. Ultimately, the ability of the placenta to balance the competing interests of mother and fetus in resource allocation may determine not only the success of pregnancy in producing viable neonates but also the long-term health of the offspring.

Sign in / Sign up

Export Citation Format

Share Document