title: Comparison insight dual X-ray absorptiometry (DXA), histomorphometry, ash weight, and morphometric indices for bone evaluation in an animal model (the orchidectomized rat) of male osteoporosis.
abstract: We have compared the measurements obtained by different methods: dual energy X-ray absorptiometry (DXA), histomorphometry, ash weight, and two morphometric indices (robusticity and bone weight/bone length index) in the orchidectomized (ORX) rat model of male osteoporosis. We examined 144 male wistar rats: 48 sham-operated, 48 ORX, and 48 ORX-treated with a bisphosphonate (risedronate) 2 or 10 mg/kg/day, 5 days per week. Rats were sacrificed at 2, 4, 8, or 16 weeks after the beginning of the study. DXA was performed on a Hologic QDR 2000 on the whole body, whole tibia, and tibial metaphysis. Bone volumes (C.BV/C.TV, and BV/TV) were measured by histomorphometry on the proximal tibial. A significant correlation was obtained between weight measured by DXA and scale (r = 0.993, P <0.000001). However, DXA underestimated weight by 0.3%. This discrepancy was dependent on the rat's weight. The weight bone length (WL) index was linearly correlated with BMD (r = 0.86), BMC (r = 0.96), and ash weight (r = 0.97). Correlation with robusticity was lower than with the WL index. A significant correlation was found between BMC of the metaphyseal region and the bone volumes but this explained only 27% of the variance; correlation with BMD was poorer (r = 0.40). BMC and ash weight were highly correlated (r = 0.992, P <0.000001). However, DXA overestimated BMC by 11% and the overestimation was found to be clearly dependent on the net mineral content of the bone.
authors.affiliation: LHEA: Laboratoire d'Histologie-Embryologie, CHU & Faculté de Médecine, 49045 Angers Cédex, France.
authors.forename: H
authors.initials: H
authors.lastname: Libouban
authors.forename: M F
authors.initials: MF
authors.lastname: Moreau
authors.forename: E
authors.initials: E
authors.lastname: Legrand
authors.forename: M F
authors.initials: MF
authors.lastname: Baslé
authors.forename: M
authors.initials: M
authors.lastname: Audran
authors.forename: D
authors.initials: D
authors.lastname: Chappard
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D001835:Body Weight / Q000502:physiology; D015519:Bone Density / Q000502:physiology*; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D002979:Climacteric / Q000378:metabolism; D004195:Disease Models, Animal; D012968:Etidronic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D007006:Hypogonadism / Q000150:complications*; D008297:Male; D009919:Orchiectomy / Q000009:adverse effects; D009929:Organ Size / Q000502:physiology*; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D011237:Predictive Value of Tests; D051381:Rats; D017208:Rats, Wistar; D000068296:Risedronic Acid; D013223:Statistics as Topic; D013977:Tibia / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology
chemical_list: D000068296:Risedronic Acid; D012968:Etidronic Acid