title: Retention of skeletal fluoride during bone turnover in rats.
abstract: Deposition of fluoride (F) in the skeleton is a major factor in the metabolic regulation of F. The progressive increase in bone F levels with age suggests that F is rather firmly sequestered once it is deposited in bone. We have examined the extent to which F is resorbed and redeposited during bone turnover in growing rats. The skeleton was first preloaded with F by intake of water containing a high level of F (50 mg F/L) and simultaneously labeled with [3H]tetracycline (3H-TC) to provide a measure of subsequent bone turnover. Rats were then changed to a very low F intake, and bone F loss was compared with 3H-TC loss in animals undergoing normal bone turnover or turnover accelerated by a low calcium (Ca) intake. Approximately 60% of F mobilized during bone resorption was redeposited in the skeleton (humerus and vertebrae). The redeposition of F showed a positive correlation with mineral deposition. Thus the retention of F in the skeleton of growing rats results predominantly from redeposition of resorbed F rather than passive retention associated with low bone turnover.
authors.affiliation: Department of Oral Biology, School of Dentistry, University of Minnesota, Minneapolis 55455.
authors.forename: M K
authors.initials: MK
authors.lastname: Guo
authors.forename: J
authors.initials: J
authors.lastname: Nopakun
authors.forename: H H
authors.initials: HH
authors.lastname: Messer
authors.forename: R
authors.initials: R
authors.lastname: Ophaug
authors.forename: L
authors.initials: L
authors.lastname: Singer
mesh_terms: D000367:Age Factors; D000818:Animals; D001835:Body Weight; D001862:Bone Resorption / Q000378:metabolism; D001842:Bone and Bones / Q000378:metabolism*; D002118:Calcium / Q000172:deficiency / Q000378:metabolism; D004032:Diet; D005459:Fluorides / Q000378:metabolism*; D051381:Rats
chemical_list: D005459:Fluorides; D002118:Calcium