Effect of sphingoid bases on basal and insulin-stimulated 2-deoxyglucose transport in skeletal muscle.
Incubation of rat soleus muscles with 50 microM sphingosine or 50 microM sphinganine augmented basal 2-deoxy-D-glucose (2DG) transport 32%, but reduced the response to 0.1 and 1.0 mU insulin/ml by 17 and 27%, respectively. When the muscles were incubated with 50 microM phytosphingosine, a 63-93% increase in basal 2DG transport was observed. However, this treatment had no effect on insulin-stimulated 2DG transport. The phytosphingosine-induced increase in basal 2-DG transport was inhibited 93 and 98% with 35 and 70 microM cytochalasin B, respectively, suggesting that it is mediated by glucose transporters. Cellular accumulation of L-glucose, which is not mediated by glucose transporters, was not affected by phytosphingosine. It is concluded that (a) both sphingosine and sphinganine increase basal 2DG transport in muscle but diminish insulin-stimulated transport, and (b) phytosphingosine stimulates basal 2DG transport in muscle by a mechanism involving glucose transporters.
Turinsky
J
J
Department of Physiology and Cell Biology, Albany Medical College, NY 12208.
Nagel
G W
GW
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D003571:Cytochalasin B / Q000494:pharmacology; D003847:Deoxyglucose / Q000378:metabolism*; D066298:In Vitro Techniques; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D009132:Muscles / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology*
D007328:Insulin; D003571:Cytochalasin B; D003847:Deoxyglucose; C012491:phytosphingosine; D013110:Sphingosine; C005682:safingol