title: Human parathyroid hormone (1-34) increases mass and structure of the cortical shell, with resultant increase in lumbar bone strength, in ovariectomized rats.
abstract: Estrogen deficiency causes reduction of bone mass and abnormal bone microarchitecture, consequently reducing bone strength. Human parathyroid hormone (hPTH) (1-34) increases bone mass and strength. To clarify the factors that determine the recovery of bone strength in the lumbar vertebrae of ovariectomized rats by intermittent hPTH administration, we analyzed the relationship between skeletal measurements and bone strength. Human PTH (1-34) administration resulted in recovery of cortical bone mineral content (BMC) and cortical bone area to sham the levels, but in resulted in a less pronounced recovery of trabecular BMC and no increase in the total cross-sectional area of the vertebral body. Of the three-dimensional (3D) trabecular bone parameters, hPTH (1-34) increased trabecular thickness (Tb.Th). The cortical shell area of L4, determined by histomorphometry, was also increased. In hPTH-treated rats, the only determinant of the compressive load of L5 was the cortical shell BMC, in the early recovery period (days 42-84). Our data suggest that increased cortical bone mass contributes more than trabecular bone mass and structure to the recovery of bone strength in response to hPTH therapy in the rat lumbar vertebral body after ovariectomy.
authors.affiliation: Department of Orthopedic Surgery, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu, Japan. s-arita@med.uoeh-u.ac.jp.
authors.forename: Shinobu
authors.initials: S
authors.lastname: Arita
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ikeda
authors.forename: Akinori
authors.initials: A
authors.lastname: Sakai
authors.forename: Nobukazu
authors.initials: N
authors.lastname: Okimoto
authors.forename: Shojiro
authors.initials: S
authors.lastname: Akahoshi
authors.forename: Masato
authors.initials: M
authors.lastname: Nagashima
authors.forename: Akifumi
authors.initials: A
authors.lastname: Nishida
authors.forename: Masako
authors.initials: M
authors.lastname: Ito
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D016723:Bone Remodeling / Q000187:drug effects*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000378:metabolism* / Q000473:pathology; D015675:Osteocalcin / Q000097:blood; D010024:Osteoporosis / Q000097:blood / Q000188:drug therapy / Q000473:pathology; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D019379:Teriparatide / Q000008:administration & dosage*
chemical_list: D015675:Osteocalcin; D019379:Teriparatide