title: Comparative effects of orchidectomy and sciatic neurectomy on cortical and cancellous bone in young growing rats.
abstract: The purpose of the present study was to compare the effects of orchidectomy and sciatic neurectomy on cortical and cancellous bone in male rats. Fifty male Sprague-Dawley rats, 6 weeks of age, were randomized into five groups, with ten rats in each group: baseline control, age-matched intact control, orchidectomy (ORX), unilateral sciatic neurectomy (NX), and ORX + NX. After 8 weeks of feeding, the tibial shaft and proximal tibia were processed for cortical and cancellous bone histomorphometric analyses, respectively. ORX-induced reductions in maturation-related cortical and cancellous bone gains were attributable to decreased periosteal bone gain and increased trabecular bone resorption, respectively. NX- and ORX + NX-induced reductions in maturation-related cortical bone gain were attributable to decreased periosteal bone formation and increased endocortical bone turnover, while NX- and ORX + NX -induced reductions in maturation-related cancellous bone gain were attributable to increased bone resorption and decreased bone formation. NX more markedly reduced maturation-related cortical and cancellous bone gains than did ORX, and the ORX-induced reductions in maturation-related cortical and cancellous bone gains were more pronounced when combined with NX. The present study demonstrated differences in changes in cortical and cancellous bone following ORX and NX in young rats. The importance of mechanical loading, with or without testosterone deficiency, is emphasized in cortical and cancellous bone growth.
authors.affiliation: Department of Sports Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Iwamoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takeda
authors.forename: Shoichi
authors.initials: S
authors.lastname: Ichimura
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sato
authors.forename: James K
authors.initials: JK
authors.lastname: Yeh
mesh_terms: D000818:Animals; D001835:Body Weight; D015519:Bone Density; D001846:Bone Development / Q000502:physiology*; D001862:Bone Resorption / Q000503:physiopathology; D005269:Femur / Q000254:growth & development; D008297:Male; D018482:Muscle, Skeletal / Q000254:growth & development; D009919:Orchiectomy / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000601:surgery*; D013977:Tibia / Q000033:anatomy & histology / Q000254:growth & development*