title: Dietary boron supplementation enhanced the action of estrogen, but not that of parathyroid hormone, to improve trabecular bone quality in ovariectomized rats.
abstract: This study investigated whether boron would enhance the ability of 17beta-estradiol (E2) or parathyroid hormone (PTH) to improve bone quality in ovariectomized OVX rats. Adult OVX rats were treated for 5 wk with vehicle, boron (5 ppm as boric acid), E2 (30 microg/kg/d, sc), PTH (60 microg/kg/d, sc), or a combination of boron and E2 or PTH, respectively. The E2 treatment corrected many adverse effects of OVX on bone quality, increased bone Ca, P, and Mg contents, and decreased trabecular plate separation. Dietary boron supplementation had no effects on these bone parameters in OVX rats. When OVX rats were treated with boron and E2 together, trabecular bone volume (Tb.BS/TV) and plate density were increased significantly more than that caused by E2 alone. The boron and E2 combination also increased trabecular bone surface (Tb.BV/TV) and decreased trabecular plate separation in OVX rats. In contrast, whereas daily PTH injection also increased bone Ca, Mg, and P contents, Tb.BV/TV, Tb.BS/TV, trabecular plate density and thickness, and decreased trabecular plate separation in OVX rats, the combination of boron and PTH had no additional improvement in bone quality over that achieved by PTH alone. In summary, this study shows for the first time that boron enhanced the action of E2, but not that of PTH, to improve trabecular bone quality in OVX rats.
authors.affiliation: Department of Human Nutrition, Foods, and Exercise, Virginia Polytechnic Institute and State University, Blacksburg 24060, USA.
authors.forename: M H
authors.initials: MH
authors.lastname: Sheng
authors.forename: L J
authors.initials: LJ
authors.lastname: Taper
authors.forename: H
authors.initials: H
authors.lastname: Veit
authors.forename: H
authors.initials: H
authors.lastname: Qian
authors.forename: S J
authors.initials: SJ
authors.lastname: Ritchey
authors.forename: K H
authors.initials: KH
authors.lastname: Lau
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D001842:Bone and Bones / Q000033:anatomy & histology / Q000187:drug effects*; D001895:Boron / Q000008:administration & dosage*; D002118:Calcium / Q000378:metabolism; D019587:Dietary Supplements; D004357:Drug Synergism; D004958:Estradiol / Q000008:administration & dosage*; D005260:Female; D008274:Magnesium / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D010052:Ovariectomy; D010281:Parathyroid Hormone / Q000008:administration & dosage*; D010758:Phosphorus / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010281:Parathyroid Hormone; D010758:Phosphorus; D004958:Estradiol; D008274:Magnesium; D001895:Boron; D002118:Calcium