Inhibition of insulin receptor binding by A23187: synergy with phorbol esters.
The ionophore A23187 inhibits the binding of insulin on U-937 monocyte-like cells which had been induced to differentiate by 1 alpha, 25-(OH)2 cholecalciferol, while it remains inactive on the undifferentiated cells. A 50% reduction of the specific binding of 125I-insulin is observed within 20 to 30 min at 37 degrees C. The effect is obtained at 10(-7)M to 10(-6)M A23187. It is reversible in 60 min at 37 degrees C. A suboptimal concentration of the ionophore potentiates the inhibitory action of phorbol esters on insulin binding.
D000001:Calcimycin / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D003593:Cytoplasm / Q000502:physiology; D004100:Dihydroxycholecalciferols / Q000494:pharmacology; D004357:Drug Synergism; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D009000:Monocytes / Q000166:cytology; D010704:Phorbols / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D011972:Receptor, Insulin / Q000187:drug effects* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D004100:Dihydroxycholecalciferols; D007328:Insulin; D010704:Phorbols; D000001:Calcimycin; D011972:Receptor, Insulin; D013755:Tetradecanoylphorbol Acetate