Control of density and microredistribution of concanavalin-A receptors in rat thymocytes at 4 degrees C.
In a previous paper, we reported that at 4 degrees C, a cooperative binding of concanavalin A to rat thymocytes is observed which corresponds to a modification of the membrane leading to the recruitment of receptors and their immobilization. In this paper, we report that both phenomena are modulated at 4 degrees C by drugs such as colchicine and cytochalasin B; cooperative binding of concanavalin A, which reflects receptor recruitment is only slightly modified by each drug alone. when the two drugs are used simultaneously, the binding of concanavalin A to rat thymocytes at low concentrations of the lectin is decreased, while at high concentrations it remains unchanged. The binding of succinyl-concanavalin A to drug-treated cells is lowered at all concentrations of lectin. Also, we have studied the effects of colchicine and cytochalacine B on the binding of horseradish peroxidase to cell-bound concanavalin A, or succinyl-concanavalin A. We have found a decreased amount of horseradish peroxidase binding to concanavalin A bound to cells treated with colchicine or cytochalasine B. In the presence of the two drugs the decrease of peroxidase binding suggested a synergistic action of colchicine and cytochalasin B.
D000818:Animals; D003078:Colchicine / Q000494:pharmacology; D003208:Concanavalin A / Q000031:analogs & derivatives / Q000378:metabolism*; D003571:Cytochalasin B / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008954:Models, Biological; D010544:Peroxidases; D051381:Rats; D011952:Receptors, Concanavalin A / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D011955:Receptors, Drug / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013696:Temperature; D013950:Thymus Gland / Q000187:drug effects / Q000378:metabolism*
D011952:Receptors, Concanavalin A; D011955:Receptors, Drug; D003208:Concanavalin A; D003571:Cytochalasin B; D010544:Peroxidases; D003078:Colchicine