ROLE OF THE CELL-MEMBRANE IN MITOSIS - EFFECTS ON HELA-CELL DIVISION OF OUABAIN, AMPHOTERICIN-B, CONCANAVALIN-A AND CYCLIC-NUCLEOTIDES

Cultured HeLa cells were treated with chemicals that affect or bind to the cell membrane (ouabain, amphotericin B and Concanavalin A) or with chemicals related to the membrane function (cyclic nucleotides). Divisions in treated cells were subsequently observed in the living state. Ouabain, at concentrations greater than 10-8M, significantly prolonged metaphase in treated cells. Excess potassium partially reversed the metaphase-prolonging effect of 10-7 M ouabain but little affected the prolongation caused by M. Amphotericin B, at 10µg per ml, also prolonged metaphase. Concanavalin A (Con A), up to 100 µg per ml, did not affect significantly mitosis. One mM N6, O2'-dibutyryl adenosine-3', 5'-cyclic monophosphate (DBcAMP) did not affect mitosis in treated cells but arrested cells in the G2 phase of the cell cycle. In the presence of theophylline 1 mM DBcAMP caused a slight but significant prolongation of metaphase, but theophylline alone effected this prolongation to the same degree. In contrast, 1 mM N6, O2' dibutyryl guanosine-3', 5'-monophosphate (DBcGMP), with or without added theophylline, significantly prolonged metaphase. © 1979, Japan Society for Cell Biology. All rights reserved.