title: Fluoride redeposition and retention during bone turnover in lactating rats.
abstract: The ability of the adult skeleton to retain fluoride (F) during times of Ca stress was assessed in lactating rats. Rats incorporated F into their skeletons throughout growth by consumption of water containing 50 ppm F from weaning to 11 weeks of age. The rats were then changed to a low-F intake and mated. At delivery, nine dams were killed as a baseline group, and 20 dams were fed a low-F diet plus distilled water during lactation. Half of the rats were subjected to the additional stress of a low-Ca intake to stimulate bone resorption. F loss was determined during lactation. Bone turnover was measured by the loss of previously incorporated tritiated tetracycline (3H-TC), and changes in bone Ca and F contents were compared with changes in 3H-TC content. The extent of bone resorption ranged from 16.5% in the humerus of the adequate-Ca group to 77.1% in the vertebrae of Ca-deficient dams. Loss of bone F was greatest in animals with greatest loss of 3H-TC. Once F was resorbed from bone, only a relatively small portion was redeposited (0-31.4%). The low extent of F redeposition appears to be related to a low Ca deposition in lactating rats.
authors.affiliation: Department of Oral Biology, School of Dentistry, University of Minnesota, Minneapolis 55455.
authors.forename: J
authors.initials: J
authors.lastname: Nopakun
authors.forename: M K
authors.initials: MK
authors.lastname: Guo
authors.forename: H H
authors.initials: HH
authors.lastname: Messer
authors.forename: R H
authors.initials: RH
authors.lastname: Ophaug
mesh_terms: D000818:Animals; D001862:Bone Resorption; D001842:Bone and Bones / Q000032:analysis / Q000378:metabolism*; D002118:Calcium / Q000172:deficiency / Q000378:metabolism*; D004032:Diet; D005260:Female; D005459:Fluorides / Q000032:analysis / Q000378:metabolism*; D007774:Lactation / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats
chemical_list: D005459:Fluorides; D002118:Calcium