title: In utero/lactational and adult exposures to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) show differential effects on craniofacial development and growth in rats.
abstract: In a previous study of female Han/Wistar (H/W) and Long-Evans (L-E) rats, we found that adult exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was associated with size decreases in the cranium and especially the face. In this study we compared these crania to those from male and female Sprague-Dawley (S-D) rats with in utero/lactational exposure to TCDD, using morphometric variables of size, shape, and fluctuating asymmetry to quantify the effects of dose on craniofacial development and growth. At the highest levels of exposure, in utero/lactational and adult TCDD exposures both resulted in small but significant reductions in facial size parameters (i.e., 3-5%) in only females and minor effects on facial shape in both sexes. The shape effects of in utero/lactational exposure were most significant at the sutural intersections, whereas adult exposure to TCDD corresponded to dose-dependent changes of decreasing facial length and vault breadth. Fluctuating asymmetry in general explained a relatively small amount of shape variation compared with other effects, and only increased significantly in female L-E rats with high levels of adult exposure to TCDD. These results indicate that TCDD-related changes in cranial development and growth in rats can vary with the timing and duration of exposure, and with sex. Further investigations of other dioxin-like compounds and animal species will broaden our understanding of how chemicals exposure can influence the development and growth of the mammalian skeleton.
authors: Department of Anthropology, National Museum of Natural History, Smithsonian Institution, 10th and Constitution Avenue NW, Washington, DC 20560, USA. Electronic address: sholtss@si.edu.
authors: Sabrina B
authors: SB
authors: Sholts
authors: National Institute for Health and Welfare, Chemicals and Health Unit, PO Box 95, FI-70701 Kuopio, Finland. Electronic address: merja.korkalainen@thl.fi.
authors: Merja
authors: M
authors: Korkalainen
authors: Andrology Laboratory, ANZAC Research Institute, University of Sydney, Sydney, NSW 2139, Australia. Electronic address: usimanainen@anzac.edu.au.
authors: Ulla
authors: U
authors: Simanainen
authors: National Institute for Health and Welfare, Chemicals and Health Unit, PO Box 95, FI-70701 Kuopio, Finland. Electronic address: hanna@nettiposti.net.
authors: Hanna M
authors: HM
authors: Miettinen
authors: Institute of Environmental Medicine, Karolinska Institutet, PO Box 210, SE-17177 Stockholm, Sweden. Electronic address: Helen.Hakansson@ki.se.
authors: Helen
authors: H
authors: Håkansson
authors: National Institute for Health and Welfare, Chemicals and Health Unit, PO Box 95, FI-70701 Kuopio, Finland; Department of Environmental Science, University of Eastern Finland, Kuopio, Finland. Electronic address: matti.viluksela@thl.fi.
authors: Matti
authors: M
authors: Viluksela
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000375:Aging; D000818:Animals; D019465:Craniofacial Abnormalities / Q000139:chemically induced / Q000473:pathology*; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000493:pharmacokinetics / Q000633:toxicity*; D005260:Female; D007774:Lactation; D050356:Lipid Metabolism / Q000187:drug effects; D008297:Male; D000072317:Polychlorinated Dibenzodioxins / Q000493:pharmacokinetics / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000473:pathology; D051381:Rats; D020318:Rats, Long-Evans; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar
chemical_list: D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins
keywords: 2,3,7,8-Tetrachlorodibenzo-p-dioxin; Bone toxicity; Craniofacial morphology; Geometric morphometrics; TCDD; in utero/lactational exposure