Alteration of calcium transport by tumor promoters, 12-O-tetradecanoyl phorbol-13-acetate and p,p'-dichlorodiphenyltrichloroethane, in the Chinese hamster V79 fibroblast cell line.
Effects of two tumor promoters, 12-O-tetradecanoyl phorbol-13-acetate (TPA) and p,p'-dichlorodiphenyltrichloroethane (DDT), on cellular calcium regulatory mechanisms were studied by using the Chinese hamster V79 fibroblast cell line. Both compounds at concentrations known to inhibit cell-cell communication, increased the cellular 45Ca2+ uptake and inhibited its efflux. DDT inhibited Ca,Mg-ATPase of the plasma membrane, while TPA stimulated cellular uptake of Ca2+. A working hypothesis has been proposed that the increase in intracellular concentration of Ca2+ by the action of these chemicals directly results in the closure of the central opening of the gap junction, and thereby causing a cessation of gap junction-mediated intercellular communication.
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002450:Cell Communication / Q000187:drug effects; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D003634:DDT / Q000494:pharmacology*; D005347:Fibroblasts; D007365:Intercellular Junctions / Q000187:drug effects; D007473:Ion Channels / Q000187:drug effects*; D010704:Phorbols / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D007473:Ion Channels; D010704:Phorbols; D003634:DDT; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium