Dislocation of Sialic Acid on Erythrocytes Membrane by nesthetics and its Blocking by SH-reagents, Colchicine r Cytochalasin B

Abstract

ABSTRACT. The cell electrophoretic mobility of rat erythrocytes decreased by treatment with thiopental or droperidol (intravenous anesthetics) at clinical concentrations.The amount of sialic acid, the main determinant of electrophoretic mobility, was not changed by the anesthetics. By using phosphate buffers of different ionic strengths, which determines the effective thickness of the ionic layer for electrophoretic mobility, translocation of sialic acid from the most peripheral zone to a deeper zone was suggested. When mobility recovered by washing out of the drugs followed by subsequent incubation, sialic acid was restored to the peripheral zone. The decrease in mobility was inhibited by sulfhydryl-blocking agents and disulfide-bridging agent. Cytochalasin B and colchicine completely blocked the mobility reduction when used single, but not when used simultaneously. These results suggest conformational changes of membrane sialoprotein by anesthetics involving sulfhydryls and cytochalasin B-and colchicine-sensitive proteins.

Further Evidence for Concanavalin A-Induced Translocation of Chondroitin Sulfate at the Cell Surface of Mammary Tumor Cells

“…Similar preventive effects of SH-blocking reagents were reported in mouse melanoma cells (8) and X-irradiated cells (15). The dislocation of acidic sugar on the cell surface also has been reported in PHA-treated lymphoblastoid cells (13), X-irradiated cells (15), and anesthetized cells (16); this suggests the involvement of contractile proteins associated with the plasma membrane (15,16). The possible involvement of the contractile proteins has been suggested in various studies of Con A (1, 2, 18, 19).…”