title: Inhibition of nitric oxide synthase blocks osteoclastic bone resorption in adaptive bone modeling.
abstract: In this study, the auditory bulla of the gerbil was pressurized, leading to active modeling of the bone of the bulla wall with a significant increase in osteoclast surface and mineral apposition rate. Systemic infusion of L-N(G)-nitro-arginine-methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS), inhibited this modeling process. The percentage osteoclast surface (Oc.S/BS) on the inner surface bulla wall was significantly reduced in the L-NAME-treated animals when compared with pressurized saline-treated bullae. Fluorescent bone surface (BSf) mineral apposition rates (MAR) and bone formation rate (BFR) were not significantly different in the pressurized bullae when the L-NAME group was compared with the control (vehicle only) group. However, L-NAME significantly suppressed BSf in the unpressurized bullae. Therefore, it is likely that nitric oxide is a mediator of osteoclastic resorption due to adaptive bone modeling through one or more of the isoforms of NOS.
authors.affiliation: Department of Otolaryngology, Washington University, St. Louis, MO 63110-1007, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Chole
authors.forename: S P
authors.initials: SP
authors.lastname: Tinling
authors.forename: E
authors.initials: E
authors.lastname: Leverentz
authors.forename: M D
authors.initials: MD
authors.lastname: McGinn
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000818:Animals; D016723:Bone Remodeling / Q000187:drug effects / Q000502:physiology*; D001862:Bone Resorption / Q000201:enzymology / Q000503:physiopathology*; D003864:Depression, Chemical; D004432:Ear, Middle / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005849:Gerbillinae; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D011312:Pressure
chemical_list: D004791:Enzyme Inhibitors; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester