title: Characterization of lymphocyte transformation induced by zinc ions.
abstract: Lymphocyte cultures from all normal human adults are stimulated by zinc ions to increase DNA and RNA synthesis and undergo blast transformation. Optimal stimulation occurs at 0.1 mM Zn(++). Examination of the effects of other divalent cations reveals that 0.01 mM Hg(++) also stimulates lymphocyte DNA synthesis. Ca(++) and Mg(++) do not affect DNA synthesis in this culture system, while Mn(++), Co(++), Cd(++), Cu(++), and Ni(++) at concentrations of 10(-7)-10(-3) M are inhibitory. DNA and RNA synthesis and blast transformation begin to increase after cultures are incubated for 2-3 days with Zn(++) and these processes reach a maximum rate after 6 days. The increase in Zn(++)-stimulated lymphocyte DNA synthesis is prevented by rendering cells incapable of DNA-dependent RNA synthesis with actinomycin D or by blocking protein synthesis with cycloheximide or puromycin. Zn(++)-stimulated DNA synthesis is also partially inhibited by 5'-AMP and chloramphenicol. Zn(++) must be present for the entire 6-day culture period to produce maximum stimulation of DNA synthesis. In contrast to its ability to independently stimulate DNA synthesis, 0.1 mM Zn(++) inhibits DNA synthesis in phytohemagglutinin-stimulated lymphocytes and L1210 lymphoblasts.
mesh_terms: D000249:Adenosine Monophosphate / Q000494:pharmacology; D002104:Cadmium / Q000494:pharmacology; D002478:Cells, Cultured; D002701:Chloramphenicol / Q000494:pharmacology; D003035:Cobalt / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D003609:Dactinomycin / Q000494:pharmacology; D003864:Depression, Chemical; D006801:Humans; D007700:Kinetics; D037102:Lectins / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects*; D008214:Lymphocytes / Q000378:metabolism; D008345:Manganese / Q000494:pharmacology; D009532:Nickel / Q000494:pharmacology; D011691:Puromycin / Q000494:pharmacology; D012313:RNA / Q000096:biosynthesis; D013268:Stimulation, Chemical; D013936:Thymidine / Q000378:metabolism; D014316:Tritium; D014529:Uridine / Q000378:metabolism; D015032:Zinc / Q000037:antagonists & inhibitors / Q000494:pharmacology*
chemical_list: D037102:Lectins; D002104:Cadmium; D014316:Tritium; D003609:Dactinomycin; D003035:Cobalt; D000249:Adenosine Monophosphate; D008345:Manganese; D011691:Puromycin; D012313:RNA; D002701:Chloramphenicol; D003300:Copper; D009532:Nickel; D004247:DNA; D003513:Cycloheximide; D015032:Zinc; D013936:Thymidine; D014529:Uridine