title: Effects of membrane-active compounds on dexamethasone binding to the glucocorticoid receptor in intact cells.
abstract: In intact rat hepatoma (HTC) cells, the binding of dexamethasone to the glucocorticoid receptor is inhibited by the calcium ionophore A23187. This effect involves both nuclear-bound and cytoplasmic receptor. Indirect evidence suggests that the inhibition requires intracellular calcium stores. Exposure of the cells to concanavalin A also inhibits dexamethasone binding. Based on earlier work in cell-free systems, it is proposed that membrane-active agents could modulate glucocorticoid hormone action at the receptor level through fluctuations in intracellular free calcium.
mesh_terms: D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D003208:Concanavalin A / Q000494:pharmacology; D003907:Dexamethasone / Q000378:metabolism*; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000187:drug effects / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism*; D013997:Time Factors
chemical_list: D011965:Receptors, Glucocorticoid; D011987:Receptors, Steroid; D003208:Concanavalin A; D000001:Calcimycin; D003907:Dexamethasone; D002118:Calcium