title: Effects of cyclic AMP on the growth of differentiating and undifferentiated Friend erythroleukemic cells.
abstract: Elevated concentrations of cyclic AMP elicit only minor reductions in growth rate and saturation density in undifferentiated Friend erythroleukemic cells. During the course of dimethylsulfoxide (DMSO)-induced differentiation, Friend cells convert from a cyclic AMP-tolerant state to a phenotype characterized by a high degree of sensitivity to cyclic AMP-mediated growth arrest. Conversion to cyclic AMP sensitivity is detectable after 30 hours growth in medium containing 2% DMSO, and either 0.5 mM 8-Br-cyclic AMP or 5 nM cholera toxin. Cultures of differentiating Friend cells achieved a stationary phase density that was approximately 8-fold higher than the cell density observed in parallel, differentiating cultures treated with 0.5 mM 8-Br-cyclic AMP. Temporally, the appearance of cyclic AMP-sensitivity corresponds to the early expression of in vitro erythroid differentiation (Ross et al., '74), but growth arrest does not alter the subsequent accumulation of hemoglobin in non-dividing DMSO-induced cells. Since growth arrest is preceded by a round of cell division, these observations are consistent with the concept that DMSO must be present during DNA replication for the subsequent expression of hemoglobin synthesis (McClintock and Papaconstantinou, '74; Levy et al., '75; Harrison, '76).
mesh_terms: D000249:Adenosine Monophosphate / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects; D002772:Cholera Toxin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004920:Erythropoiesis; D011494:Protein Kinases / Q000378:metabolism; D014970:Xanthines / Q000494:pharmacology
chemical_list: D014970:Xanthines; D000249:Adenosine Monophosphate; D002772:Cholera Toxin; D000242:Cyclic AMP; D011494:Protein Kinases; D000262:Adenylyl Cyclases; D004121:Dimethyl Sulfoxide