Nitric oxide inhibits DNA synthesis and induces activation of poly(ADP-ribose) polymerase in cultured rat hepatocytes.
Incubation of cultured rat hepatocytes with sodium nitroprusside or SIN-1, two nitric oxide (NO) donors, inhibited the mitogenic action of hepatocyte growth factor in a dose-dependent manner. The addition of 100 microM reduced hemoglobin, which is known to absorb NO, or the presence of 20 microM 1,5-isoquinolinediol, a poly(ADP-ribose) polymerase (PARP) inhibitor, decreased the cytostatic effects of SIN-1. By labeling the hepatocytes with [2-3H]adenine we studied whether nitric oxide induces ADP-ribosylation of proteins in a whole-cell system. At 0.4 mM, sodium nitroprusside increased the [3H]adenine labeling of two proteins of 116 and 130-135 kDa. This effect was time-dependent and was detected after 2 h. Only the 116-kDa protein was recognized by three different antibodies against poly (ADP-ribose) polymerase in Western blot assays. These results demonstrate that NO has antimitogenic effects in cultured hepatocytes and that its action could be mediated by PARP activation.
Facultat d'Odontologia, Universitat de Barcelona, Spain.
M
M
Dalmau
M
M
Joaquin
T
T
Nakamura
R
R
Bartrons
J
J
Gil
D000818:Animals; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D004789:Enzyme Activation / Q000187:drug effects; D017228:Hepatocyte Growth Factor / Q000037:antagonists & inhibitors; D007700:Kinetics; D008099:Liver / Q000187:drug effects* / Q000378:metabolism*; D008938:Mitosis / Q000187:drug effects; D008981:Molsidomine / Q000031:analogs & derivatives / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D051381:Rats
D009599:Nitroprusside; D009569:Nitric Oxide; C002385:linsidomine; D017228:Hepatocyte Growth Factor; D004247:DNA; D008981:Molsidomine; D011065:Poly(ADP-ribose) Polymerases