Ferricyanide can replace pyruvate to stimulate growth and attachment of serum restricted human melanoma cells

Addition of potassium ferricyanide to RPMI 1640 medium can stimulate cell attachment and replication, in a closely correlated fashion, of a human melanoma line when serum is a limiting growth factor. Ferricyanide is more effective than pyruvate on a molar basis but toxic effects at concentrations greater than 0.03mM limit its full potential. Since ferricyanide cannot itself provide nutrients for the cell and is extracellular but may be involved in transmembrane electron flow, it is suggested that its mechanism of action may be to provide energy for cell surface processes concerned with attachment and thus secondarily for replication.