Change of bone tissue composition and impaired bone strength in rats exposed to 3,3′,4,4′,5-pentachlorobiphenyl (PCB126)

• Published in: Toxicology (Amsterdam) Vol. 150; no. 1; pp. 41 - 51
• Main Authors: Lind, P.M, Larsson, S, Oxlund, H, Håkansson, H, Nyberg, K, Eklund, T, Örberg, J
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 07.09.2000; Amsterdam Elsevier Science
• Subjects: 3,3',4,4',5-Pentachlorobiphenyl; Animals; Biological and medical sciences; Biomechanical Phenomena; Biomechanics; Bone and Bones - chemistry; Bone and Bones - drug effects; Bone and Bones - metabolism; Bone and Bones/chemistry/drug effects/metabolism; Bone strength; Chemical and industrial products toxicology. Toxic occupational diseases; Collagen; Collagen - biosynthesis; Cross-links; Environmental Pollutants - toxicity; Female; Medical sciences; Medicin och hälsovetenskap; Organ Size - drug effects; Ovariectomy; PCB126; Polychlorinated Biphenyls - toxicity; Rat; Rats; Rats, Sprague-Dawley; Stiffness; Toxicology; Various organic compounds; Vitamin A; Vitamin A - analysis; Rat; 3,3′,4,4′,5-Pentachlorobiphenyl; OVX, ovariectomized; SHAM, sham-operated; D-pyr, (LP) lysyl-pyridinoline; Cross-links; PCB, polychlorinated biphenyls; Vitamin A; bw, bodyweight; PCB126, 3,3′,4,4′,5-pentachlorobiphenyl; PCB126; DDW, dry defatted weight; TCDD, 2,3,7,8-tetrachlorodibenzo- p-dioxin; Collagen; Stiffness; Pyr, (HP) hydroxylysyl-pyridinoline; Bone strength; Ovariectomy; Toxicity; Rodentia; Diseases of the osteoarticular system; Estrogen; Retinoid; Bone disease; Polychlorobiphenyl; Inorganic compound; Retinol; Osteoporosis; Vertebrata; Mammalia; Depletion; Animal; Bone; Bone matrix; Strength; Organic compounds; Rats; Sprague-Dawley
• ISSN: 0300-483X; 1879-3185; 1879-3185
• DOI: 10.1016/S0300-483X(00)00245-6

The aim of this study was to compare effects of estrogen depletion (ovariectomy) and exposure to 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) on bone strength and bone tissue composition in the rat. Half of the rats were ovariectomized ( n=20) and the remainder were sham-operated. Ten of the ovariectomized rats and ten of the sham operated were exposed to PCB126 (ip injections) for 3 months (total dose, 384 μg/kg bodyweight), while those remaining received the vehicle. The humerus and femur were used for analysis of torsional strength and biochemical studies, respectively. Both sham-operated and ovariectomized animals showed a significantly shorter bone length, lower water content and a decreased torsional stiffness when exposed to PCB126. Sham-operated rats exposed to PCB126 had lower maximum torque when compared with sham operated controls. The PCB126-exposed rats also exhibited a significantly lower collagen concentration, but showed a higher pyridinoline concentration of cortical bone. PCB126 exposure decreased the hepatic level of vitamin A but increased vitamin A levels in serum and kidneys. Ovariectomy per se increased bone length and organic content and decreased the inorganic content significantly, but did not affect any of the tested biomechanical parameters. In conclusion, this study showed that the common environmental pollutant PCB126 impaired bone strength and altered bone composition. It is hypothesized that these effects might partly be explained by PCB-induced retinoid disturbances.