| 1. |
- Andersson, Carin, et al.
(author)
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A chemometrical approach to study interactions between ethynylestradiol and an AhR-agonist in stickleback (Gasterosteus aculeatus)
- 2010
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In: Journal of Chemometrics. - : Wiley. - 0886-9383 .- 1099-128X. ; 24:11-12, s. 768-778
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Journal article (peer-reviewed)abstract
- Quantifiable responses in fish, such as induction of certain proteins, can be used as indicators of chemical contamination of waterways. In order to evaluate differences in ethoxyresorufin-O-deethylase (EROD) induction capacity of the gill and the liver and effects on organs and biomarker proteins, e.g. gill and liver EROD, hepatosomatic index (HSI), nephrosomatic index (NSI), gonadosomatic index (GSI), spiggin, vitellogenin and sperm motility were analysed in male three-spined sticklebacks (Gasterosteus aculeatus) exposed for 21 days to β-naphthoflavone (βNF) alone (Exp 1) or in combination with 17α-ethynylestradiol (EE2) (Exp 2). The sperm motility variables were studied using computer-assisted sperm analysis (CASA). Exp 1: Gill EROD activity was significantly induced in fish exposed to ≥1.2 µg/l and hepatic EROD activity in fish exposed to ≥6 µg/l. No significant effect of ßNF on the production of spiggin or vitellogenin or on sperm variables was found. Exp 2: A significant additative effect of EE2 + βNF was shown for gill EROD. A significant antagonistic effect of the two compounds was found on NSI where an increased EE2 concentration led to an increase in NSI while an increased concentration of βNF led to a decreased NSI. Interestingly, the results showed that exposure to intermediate concentrations of EE2 and ßNF led to a significant increase in the sperm variables. In the aquatic environment mixtures of numerous chemicals with oestrogenic activity are present, so if the capacity to induce gill EROD activity is a general property of oestrogen-acting chemicals, our findings are important.
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| 2. |
- Lejonklou, Margareta H., et al.
(author)
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Low-dose developmental exposure to bisphenol A alters the femoral bone geometry in wistar rats
- 2016
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In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 164, s. 339-346
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Journal article (peer-reviewed)abstract
- Background: Bisphenol A (BPA) is a chemical produced in large volumes for use in manufacturing of consumer products and industrial applications, and an endocrine disruptor known to affect several hormonal systems. Bone produces hormones and is additionally a sensitive hormone target tissue, and is thus potentially sensitive to low doses of endocrine disruptors such as BPA, especially during development. Methods: 110 pregnant Wistar rats were gavaged with 0; 25 mu g; 250 mu g; 5000 mu g or 50,000 mu g BPA/kg bodyweight (bw)/day from gestational day 7 until weaning at postnatal day 22. The three-month-old offspring were sacrificed and right femurs collected for length measurements, geometrical measurements by peripheral quantitative computed tomography (pQCT), as well as for analyses of biomechanical properties using the three-point-bending method. Results: The femur was elongated in female offspring of dams exposed to 25 or 5000 mu g BPA/kg bw/day (1.8% and 2.1%, respectively), and increased cortical thickness (4.7%) was observed in male offspring of dams exposed to 25 mu g BPA/kg bw/day, compared to controls (p < 0.005). The biomechanical properties of the bone were not significantly altered. Conclusions: In utero and lactational exposure to the lowest BPA dose used in this study altered femoral geometry in both male and female offspring. This was observed at 25 mu g BPA/kg bw/day, a dose lower than the Human Equivalent Dose (HED) applied by EFSA to set a temporary TDI (609 mu g BPA/kg bw/day), and far lower than the No-Observed-Adverse-Effect-Level (NOAEL) (5000 mu g BPA/kg bw/day) on which the US FDA TDI is based.
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| 3. |
- Lind, Monica, et al.
(author)
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Bone tissue composition, dimensions and strength in female rats given an increased dietary level of vitamin A or exposed to 3,3',4, 4',5-pentachlorobiphenyl (PCB126) alone or in combination with vitamin C.
- 2000
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In: Toxicology. - 0300-483X .- 1879-3185. ; 151:1-3, s. 11-23
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Journal article (peer-reviewed)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 microgram/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 (600000 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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| 4. |
- Lind, Monica, et al.
(author)
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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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In: Toxicology. - 0300-483X .- 1879-3185. ; 150:1-3, s. 41-51
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Journal article (peer-reviewed)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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| 5. |
- Lind, Monica, et al.
(author)
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Effects of the antiestrogenic environmental pollutant 3,3',4,4', 5-pentachlorobiphenyl (PCB #126) in rat bone and uterus : diverging effects in ovariectomized and intact animals
- 1999
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In: Toxicology and Applied Pharmacology. - : Elsevier BV. - 0041-008X .- 1096-0333. ; 154:3, s. 236-244
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Journal article (other academic/artistic)abstract
- The purpose of this study was to compare effects on rat bone and uterus of estrogen depletion and exposure to the coplanar PCB-congener 3,3',4,4',5-pentachlorobiphenyl (PCB #126) which exhibits anti-estrogenic properties. Half of the rats were ovariectomized (n = 20) and the other half were sham-operated. Ten of the ovariectomized rats and ten of the sham operated were exposed to PCB #126 (ip injections) for 3 months (total dose: 384 microgram/kg body wt). The remaining control rats were injected with corn oil (vehicle). The rats were killed and the tibiae and uteri were dissected. The left tibia was used for measurements of weight, length, and bone mineral density and the right for histomorphometrical analysis. The uteri were analyzed with respect to estrogen receptor content. PCB #126 exposure did not affect bone mineral density or trabecular bone volume of tibia in sham-operated rats. In ovariectomized rats PCB #126 exposure resulted in a decreased length and an increased bone mineral density of tibia. An obvious PCB #126 induced increase in osteoid surface was observed in sham-operated rats. The cortical thickness and the organic content of the tibia were also increased in these rats. In estrogen deprived tissue like the uteri of ovariectomized rats, PCB #126 showed weak estrogen agonistic activity. The observed effects of PCB #126 on bone and uterine tissues differed between ovariectomized and sham-operated rats.
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