Placental glucose transport in gestational diabetes mellitus.
OBJECTIVE
We have previously reported that type 1 diabetes mellitus with hyperglycemia during the first trimester is associated with an up-regulation of placental glucose transport at term. We speculated that glucose concentrations regulate placental glucose transporters only during early pregnancy. To test this hypothesis we studied placental glucose transport in gestational diabetes mellitus, which is associated with hyperglycemia mainly during the second half of pregnancy.


METHODS
Syncytiotrophoblast microvillous membrane vesicles and basal membrane vesicles were isolated from uneventful pregnancies (control group, n = 32) and pregnancies complicated by gestational diabetes mellitus (n = 18). Glucose uptake and glucose transporter 1 expression were studied by means of radiolabeled tracers and Western blotting, respectively.


RESULTS
Gestational diabetes mellitus was not associated with alterations in placental glucose transport. Separate analysis of 6 patients in the gestational diabetes mellitus group with large-for-gestational-age babies did not affect these results.


CONCLUSIONS
These findings are consistent with the hypothesis that the sensitivity of placental glucose transporters to regulation by nutrient availability is limited to early pregnancy.
Jansson
T
T
Department of Physiology, the Perinatal Center, Göteborg University, Sweden.
Ekstrand
Y
Y
Wennergren
M
M
Powell
T L
TL
D000262:Adenylyl Cyclases / Q000032:analysis; D000328:Adult; D000469:Alkaline Phosphatase / Q000032:analysis; D001692:Biological Transport; D001786:Blood Glucose / Q000032:analysis; D016640:Diabetes, Gestational / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test; D051272:Glucose Transporter Type 1; D006801:Humans; D008871:Microvilli / Q000737:chemistry / Q000378:metabolism; D009004:Monosaccharide Transport Proteins / Q000032:analysis; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D014327:Trophoblasts / Q000737:chemistry / Q000648:ultrastructure
D001786:Blood Glucose; D051272:Glucose Transporter Type 1; D009004:Monosaccharide Transport Proteins; C495677:SLC2A1 protein, human; D000469:Alkaline Phosphatase; D000262:Adenylyl Cyclases; D005947:Glucose