title: Region-specific growth effects in the developing rat prostate following fetal exposure to estrogenic ultraviolet filters.
abstract: OBJECTIVE
  Exposure to environmental endocrine disruptors is a potential risk factor for humans. Many of these chemicals have been shown to exhibit disruption of normal cellular and developmental processes in animal models. Ultraviolet (UV) filters used as sunscreens in cosmetics have previously been shown to exhibit estrogenic activity in in vitro and in vivo assays. We examined the effects of two UV filters, 4-methylbenzylidene camphor (4-MBC) and 3-benzylidene camphor (3-BC), in the developing prostate of the fetal rat.
  
  
  METHODS
  Pregnant Long Evans rats were fed diets containing doses of 4-MBC and 3-BC that resulted in average daily intakes of these chemicals corresponding to the lowest observed adverse effects level (LOAEL) and the no observed adverse effects level (NOAEL) doses in prior developmental toxicity studies. Using digital photographs of serial sections from postnatal day 1 animals, we identified, contoured, and aligned the epithelial ducts from specific regions of the developing prostate, plus the accessory sex glands and calculated the total volume for each region from three-dimensional, surface-rendered models.
  
  
  RESULTS
  Fetal exposure to 4-MBC (7.0 mg/kg body weight/day) resulted in a significant increase (p < 0.05) in tissue volume in the prostate and accessory sex glands. Treated males exhibited a 62% increase in the number of ducts in the caudal dorsal prostate. Increased distal branching morphogenesis appears to be a consequence of exposure in the ventral region, resulting in a 106% increase in ductal volume.
  
  
  CONCLUSIONS
  4-MBC exposure during development of the male reproductive accessory sex glands exhibited classical growth effects associated with estrogenic endocrine disruptors. The different regional responses suggest that the two developmental processes of ductal outgrowth and branching morphogenesis are affected independently by exposure to the environmental chemicals.
authors.affiliation: Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, South Dakota 57069, USA.
authors.forename: Luke
authors.initials: L
authors.lastname: Hofkamp
authors.forename: Sarahann
authors.initials: S
authors.lastname: Bradley
authors.forename: Jesus
authors.initials: J
authors.lastname: Tresguerres
authors.forename: Walter
authors.initials: W
authors.lastname: Lichtensteiger
authors.forename: Margret
authors.initials: M
authors.lastname: Schlumpf
authors.forename: Barry
authors.initials: B
authors.lastname: Timms
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001593:Benzyl Compounds / Q000009:adverse effects*; D002164:Camphor / Q000009:adverse effects / Q000031:analogs & derivatives*; D005260:Female; D008297:Male; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011467:Prostate / Q000187:drug effects* / Q000254:growth & development; D051381:Rats; D020318:Rats, Long-Evans; D013473:Sunscreening Agents / Q000009:adverse effects*
chemical_list: D001593:Benzyl Compounds; D013473:Sunscreening Agents; C511303:3-benzylidene camphor; D002164:Camphor; C038939:enzacamene