Fetal and placental glucose and amino acid uptake in the spontaneously hypertensive rat.
Until late in gestation, fetal spontaneously hypertensive rat (SHR) is growth retarded. Fetal growth rate increases after placental hypertrophy occurs between fetal days 18 and 20. The increase in placental mass may result in improved transfer of macro nutrients to the fetus and thus stimulate growth. In this study, fetal and placental uptake of the glucose analog 3-O-methyl glucose (3MG) and the amino acid analog amino-isobutyric acid (AIB) from the maternal circulation were compared in the SHR and Wistar-Kyoto (WKY) on days 16, 20 and 22 of gestation. Placental 3MG uptake (d/min/g tissue wet weight) was decreased in the SHR on days 20 and 22 but no differences were observed in fetal 3MG uptake. Increased placental mass in the SHR meant that total placental 3MG uptake was greater in the SHR. Placental uptake of AIB (d/min/g tissue wet weight) was much lower in the SHR (on days 16, 20 and 22) and the decrease was not compensated for by increased placental mass. Fetal uptake of AIB was decreased on days 20 and 22 (P<0.05). AIB uptake (d/min/g tissue wet weight) by the carcass and the internal organs (brain, heart, kidney, liver and lung) was also lower in the SHR. These findings indicate that although fetal growth in the SHR increases rapidly in late gestation following placental hypertrophy, it does so despite a pronounced deficit in amino acid uptake.
Research Centre for Developmental Medicine and Biology, University of Auckland, New Zealand.
R M
RM
Lewis
N S
NS
Bassett
B M
BM
Johnston
S J
SJ
Skinner
D019325:3-O-Methylglucose / Q000493:pharmacokinetics*; D000621:Aminoisobutyric Acids / Q000493:pharmacokinetics*; D000818:Animals; D001835:Body Weight / Q000502:physiology; D005260:Female; D005333:Fetus / Q000378:metabolism* / Q000502:physiology; D006973:Hypertension / Q000378:metabolism*; D009929:Organ Size; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D011918:Rats, Inbred SHR / Q000378:metabolism*; D011921:Rats, Inbred WKY; D014018:Tissue Distribution
D000621:Aminoisobutyric Acids; D019325:3-O-Methylglucose