Mechanisms mediating the antiproliferative effects of nitric oxide in cultured human airway smooth muscle cells

摘要

>We have characterised the mechanisms involved in the antiproliferative effect of NO in human airway smooth muscle cells (HASMC). S-Nitroso-N-acetyl penicillamine, a nitric oxide donor, inhibited proliferation in both G₁ and S phases of the cell cycle. Additionally, experiments with 8-bromo-cGMP, haemoglobin, a NO scavenger and zaprinast, a cGMP-specific phosphodiesterase inhibitor, showed that both effects were NO-mediated. The G₁ phase inhibition was cGMP-dependent whereas the S phase inhibition was due to a cGMP-independent inhibition of ribonucleotide reductase. These results demonstrate that NO inhibits HASMC proliferation by cGMP-dependent and -independent mechanisms acting at distinct points in the cell cycle.