Glucose transporters in isolated chromaffin cells. Effects of insulin and secretagogues.
1. Isolated chromaffin cells from bovine adrenal medulla were used to study glucose transport in a homogeneous neural tissue. 2. The affinity of glucose transporters was 1.20 +/- 0.52 mM by the infinite-cis technique and 1.02 +/- 0.09 mM by the direct transport experiments. 3. The affinity for 2-deoxyglucose of these transporters was 2.3 mM. 4. The glucose transporters, quantified by [3H]cytochalasin B binding, were 419,532 +/- 120,740 receptors/cell, which corresponds to about 7.2 +/- 2 pmol/mg of protein, with KD = 0.1 microM. 5. High-affinity insulin receptors with KD = 3.95 nM were present at a density of 68,400 +/- 7500 per cell. 6. Insulin and secretagogues increased glucose transport, raising the transporter number at the plasma membrane without changes in the affinity.
Delicado
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Miras Portugal
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D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002417:Cattle; D002469:Cell Separation; D002838:Chromaffin System / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D003847:Deoxyglucose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D009538:Nicotine / Q000494:pharmacology; D011972:Receptor, Insulin / Q000032:analysis; D011956:Receptors, Cell Surface / Q000032:analysis*
D007328:Insulin; D011956:Receptors, Cell Surface; C027786:glucose receptor; D009538:Nicotine; D003847:Deoxyglucose; D011972:Receptor, Insulin; D005947:Glucose; D000109:Acetylcholine