title: The multiplication of cells.
abstract: Cultured cells, particularly fibroblasts, have been useful for studies on control systems, since growth can be stimulated or suppressed experimentally. Combinations of mitogenic factors (hormones) in the extracellular fluid, provide positive signals for growth, potentially acting over a long range. Short range effects, such as cell-cell interactions and anchorage to substrates, also control growth but these are less well understood. A positive signal for growth, for example the binding of a mitogenic polypeptide factor to a surface receptor, leads rapidly to a complex change in cell physiology, which can be explained by an alteration of mobile cell surface complexes. This leads to an increase in probability, not certainty, of transition through an essential control point leading to chromosome replication and mitosis.
mesh_terms: D000818:Animals; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003260:Contact Inhibition; D003470:Culture Media; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D008934:Mitogens / Q000494:pharmacology; D013997:Time Factors
chemical_list: D003470:Culture Media; D008934:Mitogens