title: Effects of short-term exposure to the DDT metabolite p,p'-DDE on bone tissue in male common frog (Rana temporaria).
abstract: Experimental studies as well as studies in free-ranging animals have shown that endocrine-disrupting chemicals (EDCs) impair bone tissue composition and strength. The aim of the present study was to expand our studies on bone tissue in a new group of animals by investigating whether bone tissue in frogs is an additional potential target of EDCs. Adult male European common frogs (Rana temporaria) were divided into 5 groups (n = 20) and injected (sc, single injection) with p,p'-DDE, a total dose of 0.01, 0.1, 1, or 10 mg of p,p'-DDE/kg body weight, respectively. A control group was treated with the vehicle (corn oil). Two weeks after injection the frogs were euthanized and samples taken. The diaphysis of the excised left femur was scanned using peripheral quantitative computed tomography (pQCT) and cortical variables, such as cortical bone mineral density (BMD), cortical cross-sectional area (CSA), and periosteal circumference, were determined. In addition, biomechanical three-point bending of the bones was conducted, with the load being applied to the same point as where the pQCT measurement was performed. The results from the pQCT measurements show that bone tissue in male frogs exposed to p,p'-DDE is negatively affected. A significant decrease in cortical BMD at the diaphysis was observed in frogs exposed to 1 mg p,p'-DDE. However, the biomechanical testing of the bones showed no significant differences between exposed and control group. Although this is the only study performed to date examining the possible relationships between EDCs and negative effects on frog bones, it supports both previous experimental findings in rodents and findings in free-ranging animals.
authors: Division of Biochemical Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. Rebecca.Lundberg@ki.se
authors: Rebecca
authors: R
authors: Lundberg
authors: Björn Munro
authors: BM
authors: Jenssen
authors: Angels
authors: A
authors: Leiva-Presa
authors: Monika
authors: M
authors: Rönn
authors: Carolina
authors: C
authors: Hernhag
authors: Carolina
authors: C
authors: Wejheden
authors: Sune
authors: S
authors: Larsson
authors: Jan
authors: J
authors: Orberg
authors: P Monica
authors: PM
authors: Lind
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects; D003633:Dichlorodiphenyl Dichloroethylene / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005269:Femur / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007279:Injections, Subcutaneous; D007306:Insecticides / Q000633:toxicity*; D008297:Male; D011894:Rana pipiens; D014057:Tomography, X-Ray Computed; D018675:Toxicity Tests; D016474:Weight-Bearing
chemical_list: D007306:Insecticides; D003633:Dichlorodiphenyl Dichloroethylene