| 1. |
- Lind, Monica, et al.
(författare)
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Change of bone tissue composition and impaired bone strength in rats exposed to 3,3',4,4',5-pentachlorobiphenyl (PCB126)
- 2000
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Ingår i: Toxicology. - 0300-483X .- 1879-3185. ; 150:1-3, s. 41-51
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Tidskriftsartikel (refereegranskat)abstract
- In previous studies we have described structural and functional changes in rat bone tissue caused by 3,3′,4,4′,5-pentachlorobiphenyl (PCB126). Some of the effects caused by PCB126 resemble those found in vitamin C-deficient rats, as well as those found in rats with a high dietary intake of vitamin A. The present investigation was designed to determine if these PCB126-induced changes could be inhibited by addition of vitamin C to the drinking water and if they could be evoked by vitamin A administration. Five groups of female rats were used in this study, which lasted for 12 weeks. Three of the groups were exposed to PCB126 (total dose 320 μg/kg, bw), either alone or in combination with vitamin C added to the drinking water (1 and 10 g/l, respectively). One group was given feed with increased level of vitamin A (600 000 U/kg pellet) and the fifth group served as controls. Using peripheral quantitative computed tomography (pQCT), it was found that PCB126 increased trabecular density and cortical thickness, but reduced the trabecular area. Furthermore, maximum torque and stiffness of the humerus during torsional testing and serum osteocalcin levels were reduced by PCB126. Of the PCB126 induced effects observed, addition of vitamin C only inhibited the reduction of serum osteocalcin. Like PCB126 vitamin A supplementation increased the inorganic content and the bone density and also reduced the trabecular area and polar moment of inertia but did not increase the cortical thickness or reduce maximum torque, stiffness or serum osteocalcin level. Apparently, the effects induced by PCB126 are not mediated either via decreased vitamin C level or increased vitamin A level.
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| 2. |
- Stern, N., et al.
(författare)
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Subchronic toxicity of baltic herring oil and its fractions in the rat (III) bone tissue composition and dimension, and ratio of n-6/n-3 fatty acids in serum phospholipids
- 2005
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Ingår i: Basic Clin Pharmacol Toxicol. - : Wiley. - 1742-7835 .- 1742-7843. ; 96:6, s. 453-64
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Tidskriftsartikel (refereegranskat)abstract
- Changes in total bone mineral density determined by the bone-ash method were recently demonstrated in rats, exposed to Herring oil from the contaminated southern part of the Baltic Sea. In the present study more detailed analysis of bone structure and biomechanics was performed and obtained results were evaluated in the context of dietary factors, such as polyunsaturated fatty acids, vitamin D and vitamin A. Baltic Sea herring oil was fractionated into one relatively pollutant-free fraction (F1), and two fractions with pronounced enrichment of pollutants (F2 and F3). Female Sprague-Dawley rats were fed diets supplemented with Baltic Herring oil, its fractions, Nordic Sea capelin oil or soy oil. Femur was scanned with peripheral quantitative computed tomography (pQCT) and also tested by a mechanical compression analysis. Polyunsaturated fatty acids, vitamin A and D were analysed in serum. Rats fed the high dose of herring oil exhibited shorter femur length with decreased diaphyseal cortical bone mineral density, as well as lowered metaphyseal cross-sectional area compared to the soy oil group. Rats fed the high dose of F1 diet had increased cortical and decreased trabecular area, and higher total and trabecular bone mineral density. Rats fed the low dose of F2 diet showed similar changes associated with increased maximum load and energy absorption in compression test of the femoral metaphysis. In summary, our findings in changes of bone geometry and density could not be linked to any isolated exposure parameter, suggesting synergistic or antagonistic effects of several components of the test diets.
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