Effect of selective blockade of oxygen consumption, glucose transport, and Ca2+ influx on thyroxine action in human mononuclear cells.
The effect of selective blockade of cellular glucose transporters, Ca2+ influx, and mitochondrial oxygen consumption on thyroxine (T4)-stimulated oxygen consumption and glucose uptake was examined in human mononuclear blood cells. Blockade of glucose transporters by cytochalasin B (1 x 10(-5) mol/L) and of Ca2+ influx by alprenolol (1 x 10(-5) mol/L) and verapamil (4 x 10(-4) mol/L) inhibited T4-activated glucose uptaken and reduced T4-stimulated oxygen consumption by 20%. Uncoupling of mitochondrial oxygen consumption by azide (1 x 10(-3) mol/L) inhibited T4-stimulated oxygen consumption, but had no effect on glucose uptake. We conclude that T4-stimulated glucose uptake in human mononuclear blood cells is dependent on intact glucose transporters and Ca2+ influx, but not on mitochondrial oxygen consumption. However, oxygen consumption is, in part, dependent on intact glucose uptake.
Kvetny
J
J
Department of Clinical Chemistry, Odense University Hospital, Denmark.
Matzen
L E
LE
D000328:Adult; D000526:Alprenolol / Q000494:pharmacology; D001386:Azides / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D003571:Cytochalasin B / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism; D009000:Monocytes / Q000187:drug effects*; D010101:Oxygen Consumption / Q000187:drug effects; D019810:Sodium Azide; D013974:Thyroxine / Q000494:pharmacology*; D014700:Verapamil / Q000494:pharmacology
D001386:Azides; D003571:Cytochalasin B; D000526:Alprenolol; D019810:Sodium Azide; D014700:Verapamil; D005947:Glucose; D013974:Thyroxine; D002118:Calcium