title: Effect of cold storage on in vitro human skin absorption of six 14C-radiolabeled environmental contaminants: benzo[a]pyrene, ethylene glycol, methyl parathion, naphthalene, nonyl phenol, and toluene.
abstract: Dermal absorption of human breast skin obtained fresh from a local hospital was tested before and after freezer storage at -19 degrees C for 30 or 60 d. Dermatomed skin (0.4-0.5 mm) was tested in vitro using the Bronaugh flow-through diffusion cells perfused at 1.5 ml/h with receiver solution (Hanks HEPES buffered basal saline containing 4% bovine serum albumin [BSA]). Six 14C-radiolabeled chemicals ranging in lipophilicity were tested, including benzo[a]pyrene (BaP), ethylene glycol (EG), methyl parathion (MP), naphthalene (Nap), nonyl phenol (NP), and toluene (Tol). There was significantly lower percent dermal absorption into the receiver solution for two of the six chemicals (BaP and Tol) with the skin depot excluded. However, with percent dermal absorption defined as that including the skin depot, with the exception of the BaP data for skin frozen 30 d, there was no significant difference between percent dermal absorption data for fresh unfrozen controls and those stored frozen for all 6 test chemicals for both 30 and 60 d freezer storage times. These results suggested with skin depot included that freezer storage may have potential for preserving human skin for in vitro absorption tests of environmental contaminants; however, optimal freezer storage conditions such as temperature and storage duration and their effects on skin viability and dermal metabolism need to be determined.
authors.affiliation: Systemic Toxicology and Pharmacokinetics Section, Environmental Occupational and Toxicology Division, Health Canada, Ottawa, Ontario, Canada. rick_moody@hc-sc.gc.ca
authors.forename: Richard P
authors.initials: RP
authors.lastname: Moody
authors.forename: Anna
authors.initials: A
authors.lastname: Yip
authors.forename: Ih
authors.initials: I
authors.lastname: Chu
mesh_terms: D001564:Benzo(a)pyrene / Q000493:pharmacokinetics; D003080:Cold Temperature; D004785:Environmental Pollutants / Q000493:pharmacokinetics*; D019855:Ethylene Glycol / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D008743:Methyl Parathion / Q000493:pharmacokinetics; D009281:Naphthalenes / Q000493:pharmacokinetics; D010636:Phenols / Q000493:pharmacokinetics; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption / Q000502:physiology*; D014021:Tissue Preservation; D014050:Toluene / Q000493:pharmacokinetics; D014481:United States; D014484:United States Environmental Protection Agency
chemical_list: D004785:Environmental Pollutants; D009281:Naphthalenes; D010636:Phenols; C031721:naphthalene; D001564:Benzo(a)pyrene; D014050:Toluene; D008743:Methyl Parathion; C025256:nonylphenol; D019855:Ethylene Glycol