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.
Dalmau
M
M
Facultat d'Odontologia, Universitat de Barcelona, Spain.
Joaquin
M
M
Nakamura
T
T
Bartrons
R
R
Gil
J
J
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