title: Low NO concentrations inhibit osteoclast formation in mouse marrow cultures by cGMP-dependent mechanism.
abstract: 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.
authors.affiliation: Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: L S
authors.initials: LS
authors.lastname: Holliday
authors.forename: A D
authors.initials: AD
authors.lastname: Dean
authors.forename: R H
authors.initials: RH
authors.lastname: Lin
authors.forename: J E
authors.initials: JE
authors.lastname: Greenwald
authors.forename: S L
authors.initials: SL
authors.lastname: Gluck
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D001854:Bone Marrow Cells; D001862:Bone Resorption; D003994:Bucladesine / Q000494:pharmacology; D002117:Calcitriol / Q000494:pharmacology; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D003804:Dentin / Q000502:physiology*; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D006146:Guanidines / Q000494:pharmacology; D066298:In Vitro Techniques; D051379:Mice; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000494:pharmacology / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009599:Nitroprusside / Q000494:pharmacology*; D010010:Osteoclasts / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D010396:Penicillamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D011688:Purinones / Q000494:pharmacology; D026423:S-Nitroso-N-Acetylpenicillamine; D014907:Whales
chemical_list: D006146:Guanidines; D011688:Purinones; D009599:Nitroprusside; D015124:8-Bromo Cyclic Adenosine Monophosphate; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; D003995:Dibutyryl Cyclic GMP; D003994:Bucladesine; D026423:S-Nitroso-N-Acetylpenicillamine; D019001:Nitric Oxide Synthase; D002117:Calcitriol; D010396:Penicillamine; C011145:zaprinast; D006152:Cyclic GMP; C004479:pimagedine; D019331:NG-Nitroarginine Methyl Ester