Phospholipid-induced inhibition of insulin-stimulated glucose transport in isolated adipocytes: interactions of phospholipids with inhibitors of glucose transport and insulinmimetic agents.
Upon interaction with phospholipid vesicles containing phosphatidylserine, isolated rat adipocytes demonstrate an inhibition of insulin-stimulated hexose uptake. In order to elucidate the mechanism of this effect, adipocytes were treated with agents, alone or in combination with vesicles, which affected the insulin-sensitive response at the receptor and post-receptor level. The effect of vesicles at a maximal inhibitory concentration proved to be non-additive with dexamethasone, suggesting that vesicles may act in a manner similar to this agent. In contrast, fat cells treated with vesicles and N-ethylmaleimide (NEM) or trypsin at submaximally effective concentrations demonstrate a partially additive inhibition of insulin-stimulated 2-deoxyglucose uptake. Vesicle treatment of adipocytes before stimulation with agents which mimic insulin, such as Con A and H2O2, demonstrates the same effects as insulin with respect to hexose uptake. These results support the contention that vesicles inhibit insulin action at least partially at the post-receptor level, and may directly interfere with the hexose transport site.
D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D003847:Deoxyglucose / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D009004:Monosaccharide Transport Proteins / Q000378:metabolism; D010743:Phospholipids / Q000494:pharmacology*; D051381:Rats; D014357:Trypsin
D007328:Insulin; D009004:Monosaccharide Transport Proteins; D010743:Phospholipids; D003208:Concanavalin A; D003907:Dexamethasone; D003847:Deoxyglucose; D006861:Hydrogen Peroxide; D014357:Trypsin; D005947:Glucose; D005033:Ethylmaleimide