Carrier-mediated uptake of hexoses by the rat visceral yolk sac.
The rat visceral yolk sac is shown to possess a sodium-independent, phloretin-sensitive, and phlorizin- and ouabain-insensitive transport system for hexoses. The rate of uptake of (3H)2-deoxy-D-glucose was measured in vitro and shown to be greatest on the 12th day, decreasing progressively with increasing gestational age up to the 20th day. Little uptake of 3-O-methyl-D-glucose, alpha-methylglucoside or L-glucose occurred. On uptake by the visceral yolk sac, 2-deoxy-D-glucose was phosphorylated, leading to considerable accumulation of this sugar. Several sugars inhibited 2-deoxy-D-glucose uptake as follows: D-glucose = mannose greater than fructose greater than galactose greater than xylose greater than fucose.
Koszalka
T R
TR
Stein Research Center, Harry Bock Laboratories, Department of Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Andrew
C L
CL
Lloyd
J B
JB
Brent
R L
RL
D019325:3-O-Methylglucose; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D003847:Deoxyglucose / Q000493:pharmacokinetics; D005260:Female; D005865:Gestational Age; D005947:Glucose / Q000493:pharmacokinetics; D006601:Hexoses / Q000493:pharmacokinetics*; D008757:Methylglucosides / Q000493:pharmacokinetics; D009005:Monosaccharides / Q000494:pharmacology; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D015017:Yolk Sac / Q000378:metabolism*
D002352:Carrier Proteins; D006601:Hexoses; D008757:Methylglucosides; D009005:Monosaccharides; D019325:3-O-Methylglucose; C027020:methylglucoside; D003847:Deoxyglucose; D005947:Glucose