The genetic influence on bone susceptibility to fluoride.
BACKGROUND
The influence of genetic background on bone architecture and mechanical properties is well established. Nevertheless, to date, only few animal studies explore an underlying genetic basis for extrinsic factors effect such as fluoride effect on bone metabolism.


METHODS
This study assessed the effect of increasing fluoride doses (0 ppm, 25 ppm, 50 ppm, 100 ppm) on the bone properties in 3 inbred mouse strains that demonstrate different susceptibilities to developing enamel fluorosis (A/J a "susceptible" strain, 129P3/J a "resistant" strain and SWR/J an "intermediate" strain). Fluoride concentrations were determined in femora and vertebral bodies. Bone mineral density was evaluating through DEXA. Finally, three-point bend testing of femora, compression testing of vertebral bodies and femoral neck-fracture testing were performed to evaluate mechanical properties.


RESULTS
Concordant with increasing fluoride dose were significant increases of fluoride concentration in femora and vertebral bodies from all 3 strains. Fluoride treatment had little effect on the bone mineral densities (BMD) in the 3 strains. Mechanical testing showed significant alterations in "bone quality" in the A/J strain, whereas moderate alterations in "bone quality" in the SWR/J strain and no effects in the 129P3/J strain were observed.


CONCLUSIONS
The results suggest that genetic factors may contribute to the variation in bone response to fluoride exposure and that fluoride might affect bone properties without altering BMD.
Mousny
M
M
Orthopaedic Research Laboratory, Cliniques Universitaires Saint-Luc, Catholic University of Louvain, Brussels, Belgium.
Banse
X
X
Wise
L
L
Everett
E T
ET
Hancock
R
R
Vieth
R
R
Devogelaer
J P
JP
Grynpas
M D
MD
D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000187:drug effects; D001842:Bone and Bones / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005272:Femur Neck / Q000187:drug effects / Q000502:physiology; D005459:Fluorides / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008805:Mice, Inbred A; D008815:Mice, Inbred Strains; D013045:Species Specificity; D013131:Spine / Q000187:drug effects / Q000502:physiology; D013314:Stress, Mechanical
D005459:Fluorides