title: Intermittent treatments of prostaglandin E2 plus risedronate and prostaglandin E2 alone are equally anabolic on tibial shaft of ovariectomized rats.
abstract: Effects of intermittent administration of prostaglandin E2 (PGE2), risedronate (Ris) and their combination on bone mass were studied on the cortical bone of tibial shafts of ovariectomized (ovx) rats. Six month old ovx rats were treated immediately after operation with subcutaneous injections of 6 mg PGE2/kg/d, 5 micrograms Ris/kg/2x/wk or their combination for 60 days each of an on/off/on cycle. PGE2 alone and in combination with Ris added the same amount of new bone in the first 60 days on period. During the 60 days off period, newly added endocortical and marrow trabecular bone disappeared in PGE2 alone treatment groups. In co-treatment group, the marrow trabeculae were only partly lost. There was no difference in total bone area between co-treatment and PGE2 alone groups after another 60 days on treatment. Our findings indicate that co-treatment was better in the maintenance of newly added endocortical and marrow trabecular bone during the off period; however, it formed less bone than PGE2 alone during the second treatment period, and ended up with the same amount of bone with both treatments.
authors.affiliation: Radiobiology Division, University of Utah, Salt Lake City 84112, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Pan
authors.forename: W S
authors.initials: WS
authors.lastname: Jee
authors.forename: Y F
authors.initials: YF
authors.lastname: Ma
authors.forename: J E
authors.initials: JE
authors.lastname: McOsker
authors.forename: X J
authors.initials: XJ
authors.lastname: Li
mesh_terms: D000818:Animals; D001846:Bone Development / Q000187:drug effects*; D001853:Bone Marrow / Q000187:drug effects; D015232:Dinoprostone / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D012968:Etidronic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D010052:Ovariectomy; D010053:Ovary / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000068296:Risedronic Acid; D013977:Tibia / Q000187:drug effects* / Q000378:metabolism
chemical_list: D015232:Dinoprostone; D000068296:Risedronic Acid; D012968:Etidronic Acid