Send to:

Choose Destination
See comment in PubMed Commons below
Am J Physiol. 1997 Mar;272(3 Pt 2):F283-91.

Low NO concentrations inhibit osteoclast formation in mouse marrow cultures by cGMP-dependent mechanism.

Author information

  • 1Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.


High concentrations of nitric oxide (NO) inhibit bone resorption by mature osteoclasts. We examined the effects of low NO concentrations on osteoclast formation in mouse bone marrow cultures. The NO releasers sodium nitroprusside (SNP) and S-nitroso-N-acetyl-DL-penicillamine inhibited the formation of multinucleated cells expressing tartrate-resistant acid phosphatase (a marker for osteoclasts) when administered during the last 3 days of 6-day cultures (differentiation stage) but not during the first 3 days (proliferation stage). SNP (1 microM) completely inhibited pit formation on dentine wafers when added to cultures during osteoclast formation, but 100 microM SNP was required to inhibit pitting by mature osteoclasts. Conversely, the NO synthase inhibitors aminoguanidine and nitro-L-arginine methyl ester both increased osteoclast formation. Inhibition of osteoclast formation by NO likely was guanosine 3',5'-cyclic monophosphate (cGMP) dependent, as SNP increased cGMP in marrow cultures, and 1 mM 8-bromo-cGMP or dibutyryl-cGMP reduced osteoclast formation when administered during the differentiation stage. The cGMP-specific type V phosphodiesterase inhibitor, zaprinast (M & B 22948) also inhibited osteoclast formation (half-maximal inhibitory constant, 100 microM) only when added during the differentiation stage. We conclude that the differentiation stage of osteoclast formation is inhibited by increases in cGMP levels elicited by NO.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk