Isopentenyladenosine stimulates and inhibits mitosis of human lymphocytes treated with phytohemagglutinin.
The plant cytokinin isopentenyladenosine, a component of yeast and mammalian transfer ribonucleic acid, is both a potent inhibitor and stimulator of DNA synthesis, transformation, and mitosis of the phytohemagglutinin-stimulated lymphocyte. The stage of the cell cycle and the concentrations used are critical for these effects. The addition of isopentenyladenosine within the first 12 hours after phytohemagglutinin at a concentration above 10(-6) molar results in inhibition, while lower concentrations (between 10(-7) and 10(-6) molar), added at 24 hours or later, have a stimulatory effect.
D000225:Adenine / Q000494:pharmacology; D002471:Cell Transformation, Neoplastic; D046508:Culture Techniques; D004261:DNA Replication / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D037102:Lectins / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects*; D008938:Mitosis / Q000187:drug effects*; D009705:Nucleosides / Q000494:pharmacology*; D012343:RNA, Transfer
D007166:Immunosuppressive Agents; D037102:Lectins; D009705:Nucleosides; D012343:RNA, Transfer; D000225:Adenine