TY - JOUR
T1 - Mineral density and biomechanical properties of bone tissue from male Arctic foxes (Vulpes lagopus) exposed to organochlorine contaminants and emaciation
AU - Sonne, Christian
AU - Wolkers, Hans
AU - Rigét, Frank F
AU - Jensen, Jens-Erik Beck
AU - Teilmann, Jenni
AU - Jenssen, Bjørn Munro
AU - Fuglei, Eva
AU - Ahlstrøm, Øystein
AU - Dietz, Rune
AU - Muir, Derek C G
AU - Jørgensen, Even H
PY - 2008
Y1 - 2008
N2 - We investigated the impact from dietary OC (organochlorine) exposure and restricted feeding (emaciation) on bone mineral density (BMD; g hydroxy-apatite cm(-2)) in femoral, vertebrate, skull and baculum osteoid tissue from farmed Arctic blue foxes (Vulpes lagopus). For femur, also biomechanical properties during bending (displacement [mm], load [N], energy absorption [J] and stiffness [N/mm]) were measured. Sixteen foxes (EXP) were fed a wet food containing 7.7% OC-polluted minke whale (Balaenoptera acutorostrata) blubber in two periods of body fat deposition (Aug-Dec) and two periods of body fat mobilisation (Jan-July) in which the food contained less energy and only 2% blubber. SigmaOC food concentration in the food containing 7.7% whale blubber was 309 ng/g wet mass. This corresponded to a SigmaOC exposure of ca. 17 microg/kg body mass/d and a responding SigmaOC residue in subcutaneous adipose tissue of ca. 1700 ng/g live mass in the 8 EXP fat foxes euthanized after 16 months. A control group (CON) composed of 15 foxes were fed equal daily caloric amounts of clean pork (Sus scrofa) fat. After 16 months, 8 EXP and 7 CON foxes were euthanized (mean body mass=9.25 kg) while the remaining 8 EXP and 8 CON foxes were given restricted food rations for 6 months resulting in a body weight reduction (mean body mass=5.46 kg). The results showed that only BMD(skull) vs. BMD(vertebrae) were significantly correlated (R=0.68; p=0.03; n=10) probably due to a similar composition of trabecular and cortical osteoid tissue. No difference in any of the BMD measurements or femoral biomechanical properties was found between EXP and CON foxes although BMD baculum was 1.6-folds lower in the EXP group. However, lean summer foxes had significantly lower femoral biomechanical properties measured as displacement (mm), energy absorption (J) and time (s) biomechanical properties than fat winter foxes (all p<0.004). This indicates lower stiffness and softer bones from fasting which is in agreement with previous studies. Further, it should be kept in mind when studying bone tissues in Arctic mammals also in order to avoid confounding effects from body condition.
AB - We investigated the impact from dietary OC (organochlorine) exposure and restricted feeding (emaciation) on bone mineral density (BMD; g hydroxy-apatite cm(-2)) in femoral, vertebrate, skull and baculum osteoid tissue from farmed Arctic blue foxes (Vulpes lagopus). For femur, also biomechanical properties during bending (displacement [mm], load [N], energy absorption [J] and stiffness [N/mm]) were measured. Sixteen foxes (EXP) were fed a wet food containing 7.7% OC-polluted minke whale (Balaenoptera acutorostrata) blubber in two periods of body fat deposition (Aug-Dec) and two periods of body fat mobilisation (Jan-July) in which the food contained less energy and only 2% blubber. SigmaOC food concentration in the food containing 7.7% whale blubber was 309 ng/g wet mass. This corresponded to a SigmaOC exposure of ca. 17 microg/kg body mass/d and a responding SigmaOC residue in subcutaneous adipose tissue of ca. 1700 ng/g live mass in the 8 EXP fat foxes euthanized after 16 months. A control group (CON) composed of 15 foxes were fed equal daily caloric amounts of clean pork (Sus scrofa) fat. After 16 months, 8 EXP and 7 CON foxes were euthanized (mean body mass=9.25 kg) while the remaining 8 EXP and 8 CON foxes were given restricted food rations for 6 months resulting in a body weight reduction (mean body mass=5.46 kg). The results showed that only BMD(skull) vs. BMD(vertebrae) were significantly correlated (R=0.68; p=0.03; n=10) probably due to a similar composition of trabecular and cortical osteoid tissue. No difference in any of the BMD measurements or femoral biomechanical properties was found between EXP and CON foxes although BMD baculum was 1.6-folds lower in the EXP group. However, lean summer foxes had significantly lower femoral biomechanical properties measured as displacement (mm), energy absorption (J) and time (s) biomechanical properties than fat winter foxes (all p<0.004). This indicates lower stiffness and softer bones from fasting which is in agreement with previous studies. Further, it should be kept in mind when studying bone tissues in Arctic mammals also in order to avoid confounding effects from body condition.
U2 - http://dx.doi.org/10.1016/j.cbpc.2008.07.015
DO - http://dx.doi.org/10.1016/j.cbpc.2008.07.015
M3 - Journal article
SN - 1532-0456
VL - 149
SP - 97
EP - 103
JO - Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology
JF - Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology
IS - 1
ER -