title: Reconstructing temporal variation of fluoride uptake in eastern grey kangaroos (Macropus giganteus) from a high-fluoride area by analysis of fluoride distribution in dentine.
abstract: Trace element profiling in the incrementally formed dentine of mammalian teeth can be applied to reconstruct temporal variation of incorporation of these elements into the tissue. Using an electron microprobe, this study analysed fluoride distribution in dentine of first and third mandibular molars of free-ranging eastern grey kangaroos inhabiting a high-fluoride area, to assess temporal variation in fluoride uptake of the animals. Fluoride content in the early-formed dentine of first molars was significantly lower than in the late-formed dentine of these teeth, and was also lower than in both, the early and the late-formed dentine of third molars. As early dentine formation in M1 takes place prior to weaning, this finding indicates a lower dentinal fluoride uptake during the pre-weaning compared to the post-weaning period. This is hypothetically attributed to the action of a partial barrier to fluoride transfer from blood to milk in lactating females and a low bioavailability of fluoride ingested together with milk. Another factor contributing to lower plasma fluoride levels in juveniles compared to adults is the rapid clearance of fluoride from blood plasma in the former due to their intense skeletal growth. The combined action of these mechanisms is considered to explain why in kangaroos from high-fluoride areas, the (early-formed) first molars are not affected by dental fluorosis while the (later-formed) third and fourth molars regularly exhibit marked to severe fluorotic lesions.
authors.affiliation: Department of Biology, University of Hildesheim, Universitätsplatz 1, 31141 Hildesheim, Germany. Electronic address: kierdorf@uni-hildesheim.de.
authors.forename: Horst
authors.initials: H
authors.lastname: Kierdorf
authors.affiliation: Deutsches GeoForschungsZentrum GFZ, Section 4.2, Telegrafenberg, 14473 Potsdam, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Rhede
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 250 Princes Hwy, Werribee, 3030, Victoria, Australia.
authors.forename: Clare
authors.initials: C
authors.lastname: Death
authors.affiliation: Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 250 Princes Hwy, Werribee, 3030, Victoria, Australia.
authors.forename: Jasmin
authors.initials: J
authors.lastname: Hufschmid
authors.affiliation: Department of Biology, University of Hildesheim, Universitätsplatz 1, 31141 Hildesheim, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Kierdorf
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D003804:Dentin; D004785:Environmental Pollutants / Q000032:analysis / Q000378:metabolism*; D005260:Female; D005459:Fluorides / Q000032:analysis / Q000378:metabolism*; D007774:Lactation; D007614:Macropodidae / Q000378:metabolism*; D010710:Phosphates
chemical_list: D004785:Environmental Pollutants; D010710:Phosphates; C012980:fluorophosphate; D005459:Fluorides
keywords: Biomonitoring; Dental fluorosis; Environmental pollution; Marsupials; Teeth