The effect of maternal hypoaminoacidaemia on placental uptake and transport of amino acids in pregnant sheep.
We developed a model of maternal hyperglycaemia with secondary hyperinsulinaemia and hypoaminoacidaemia in pregnant sheep (H) to determine the effect of these conditions on uterine, uteroplacental and fetal amino-acid uptake rates and fetal amino-acid concentrations [AA]. Results were compared with normal pregnant ewes (C). Plasma glucose concentrations were greater in H versus C animals: 7.7+/-0.3 versus 3.9+/-0.1 mmol/l maternal, P< 0.005; 2.6+/-0.1 versus 1.1+/-0.1 mmol/l fetal, P< 0.005. Maternal insulin concentrations [I] were greater in the H group (132+/-30 H versus 31+/-5 C microU/ml, P< 0.005); fetal [I] were not different (15+/-2 H versus 16+/-2 C microU/mL). Maternal [AA] were lower in H than C groups except for SER (P=ns) and GLY (approx twofold higher, P< 0.01). Uterine, uteroplacental and fetal uptake rates of several AA, particularly the branch chain AA, were lower in H than C animals, producing lower total fetal nitrogen uptake rates (270+/-64 mg N/kg fetus/day H, 696+/-75 mg N/kg fetus/day C, P=0.001) and lower fetal plasma concentrations for the branch chain AA. Most fetal [AA], however, remained at control values, which could occur by relative increase in fetal amino-acid production and/or decrease in utilization, but not by increased uteroplacental transport rates.
Thureen
P J
PJ
The Perinatal Research Center, Department of Pediatrics, University of Colorado Health Sciences Center, 4200 East 9th Avenue, Denver, CO 80262, USA. patti.thureen@uchsc.edu
Padbury
J F
JF
Hay
W W
WW
D000596:Amino Acids / Q000097:blood / Q000172:deficiency* / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D005260:Female; D005333:Fetus / Q000378:metabolism; D005865:Gestational Age; D006943:Hyperglycemia / Q000378:metabolism; D006946:Hyperinsulinism / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D012756:Sheep; D013997:Time Factors
D000596:Amino Acids; D009584:Nitrogen