Short-term exposure to dioxin impairs bone tissue in male rats.
Chronic and sub-chronic studies in rats have previously shown that dioxin-like compounds impair the bone tissue homeostasis. In the present study, tibiae and serum were analyzed to study possible effects of short term dioxin exposure on rats. Two month old (ca. 200g) male rats were injected with 50microg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) kg(-1) bw and tibiae were excised 5d following the exposure. Bone composition, dimensions and strength were analyzed by pQCT and three-point bending test on tibiae. In addition, detailed bone composition was analyzed by optical emission spectroscopy (ICP-OES) and Fourier transform infrared spectrometry (FTIR). Analysis of the serum bone biomarkers procollagen type-I N-terminal propeptide (PINP) and carboxyterminal cross linking teleopeptide (CTX) were also performed. pQCT-results showed alterations in the metaphysis, with a significant decrease in trabecular bone cross-sectional area (-19%, p<0.05) and a significant increase in total bone mineral density (+7%, p<0.05) in TCDD-exposed rats. Analyses of the bones by ICP-OES and FTIR showed that bones from exposed rats had a higher relative proportion of crystalline phosphate (+13% for a1080 and +11% for a1113, p<0.05) and lower acid phosphate content (-22% for a1145, p<0.05), resembling the composition of more mature bones. Serum analysis showed that the bone formation marker PINP was decreased (-37%, p<0.05) and that the bone resorption marker CTX was increased (+14%, p<0.05) indicating a net loss of bone tissue. In conclusion, 5d of exposure to TCDD was sufficient to negatively affect bone tissue in male rats.
Lind
P Monica
PM
Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, Nobels väg 13, plan 3, Box 210, S-171 77 Stockholm, Sweden. Electronic address: Monica.Lind@ki.se.
Wejheden
Carolina
C
Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, Nobels väg 13, plan 3, Box 210, S-171 77 Stockholm, Sweden.
Lundberg
Rebecca
R
Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, Nobels väg 13, plan 3, Box 210, S-171 77 Stockholm, Sweden.
Alvarez-Lloret
Pedro
P
Departamento de Mineralogía y Petrología, Facultad de Ciencias, Universidad de Granada, Avenida Fuentenueva s/n, 18071 Granada, Spain.
Hermsen
Sanne A B
SAB
Institute of Environmental Medicine, Division of Biochemical Toxicology, Karolinska Institutet, Nobels väg 13, plan 3, Box 210, S-171 77 Stockholm, Sweden.
Rodriguez-Navarro
Alejandro B
AB
Departamento de Mineralogía y Petrología, Facultad de Ciencias, Universidad de Granada, Avenida Fuentenueva s/n, 18071 Granada, Spain.
Larsson
Sune
S
Department of Surgical Sciences, Orthopaedics, Uppsala University, Sweden.
Rannug
Agneta
A
Institute of Environmental Medicine, Division of Work Environment Toxicology, Karolinska Institutet, Box 210, S-171 77 Stockholm, Sweden.
D000818:Animals; D015519:Bone Density / Q000187:drug effects; D001842:Bone and Bones / Q000187:drug effects*; D008297:Male; D010710:Phosphates / Q000378:metabolism; D010748:Phosphopeptides / Q000097:blood; D000072317:Polychlorinated Dibenzodioxins / Q000008:administration & dosage / Q000031:analogs & derivatives*; D011347:Procollagen / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D017550:Spectroscopy, Fourier Transform Infrared; D013977:Tibia / Q000187:drug effects; D014057:Tomography, X-Ray Computed
C062121:N-propeptide type I collagen; D010710:Phosphates; D010748:Phosphopeptides; D000072317:Polychlorinated Dibenzodioxins; D011347:Procollagen