title: Decrease in particle-induced osteolysis in ovariectomized mice.
abstract: Postmenopausal osteoporosis is a common disorder that results from increased osteoclastic activity caused by estrogen deficiency. Whether postmenopausal bone remodeling can alter the response to particulate debris is unknown. The purpose of this study was to evaluate the bone response to polyethylene particles in an ovariectomized murine model. Polyethylene particles were implanted onto the calvaria of seven control mice and seven ovariectomized (OVX) mice, as compared with calvaria from sham-operated and OVX mice. Calvaria were harvested after 14 days. Skulls were analyzed with a high-resolution micro-CT and by histomorphometry after staining with Stevenel blue and picrofuschine, and for tartrate-specific alkaline phosphatase. As assessed by micro-CT, particle implantation induced a significant decrease in bone thickness in control mice, while bone thickness remained stable in OVX mice. In particle-implanted animals, the osteoclast number was 2.84 +/- 0.3 in control mice and 1.74 +/- 0.22 in OVX mice. Mean bone loss was -12% +/- 1.9% in control mice and -4.7% +/- 1.7% in OVX animals. The reduction of osteolytic response suggests that ovariectomy may have a protective role against particle-induced bone resorption.
authors.affiliation: Laboratoire de Recherche Orthopédique, Faculté de Médecine Paris VII-Denis Diderot, 75010 Paris, France. chrnich@gmail.com
authors.forename: Christophe
authors.initials: C
authors.lastname: Nich
authors.forename: Arnaud
authors.initials: A
authors.lastname: Marchadier
authors.forename: Laurent
authors.initials: L
authors.lastname: Sedel
authors.forename: Hervé
authors.initials: H
authors.lastname: Petite
authors.forename: Catherine
authors.initials: C
authors.lastname: Vidal
authors.forename: Moussa
authors.initials: M
authors.lastname: Hamadouche
mesh_terms: D000818:Animals; D019643:Arthroplasty, Replacement / Q000009:adverse effects / Q000295:instrumentation; D016723:Bone Remodeling / Q000187:drug effects; D004195:Disease Models, Animal; D005260:Female; D050723:Fractures, Bone / Q000209:etiology / Q000601:surgery; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D010010:Osteoclasts / Q000187:drug effects; D010014:Osteolysis / Q000139:chemically induced* / Q000503:physiopathology*; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D010052:Ovariectomy / Q000009:adverse effects; D052638:Particulate Matter / Q000009:adverse effects*; D020959:Polyethylene / Q000009:adverse effects*; D011474:Prosthesis Design / Q000009:adverse effects; D011475:Prosthesis Failure; D012886:Skull / Q000187:drug effects
chemical_list: D052638:Particulate Matter; D020959:Polyethylene