title: Early changes produced in mouse skin by the application of three middle distillates.
abstract: It has been reported by the American Petroleum Institute (API) that dermal applications of certain middle distillates of mineral oils can result in high incidences of skin tumours in mice. This was unexpected as the polycyclic aromatic hydrocarbon (PAH) levels in these were below detection limits. To examine the possible role of tissue injury in the induction of tumours, the skin reactions produced by thrice weekly applications of three middle distillates similar to those tested by the API were examined grossly and histopathologically at intervals up to 6 weeks. Various reference materials and oils were used as controls. Preliminary histological examination showed that severe skin damage was present from week 1 onwards in mice treated with the three middle distillates, two of them producing epidermal loss and ulceration. Marked epidermal hyperplasia was produced by all three middle distillates. These findings support the view that regenerative epidermal hyperplasia due to repeated severe skin damage may have exerted a powerful promotional effect in the production of the skin tumours by middle distillates in the API study.
authors.affiliation: Robens Institute of Industrial and Environmental Health and Safety, University of Surrey, Guildford, U.K.
authors.forename: P
authors.initials: P
authors.lastname: Grasso
authors.forename: M
authors.initials: M
authors.lastname: Sharratt
authors.forename: A J
authors.initials: AJ
authors.lastname: Ingram
mesh_terms: D000818:Animals; D003436:Croton Oil / Q000633:toxicity; D006965:Hyperplasia / Q000139:chemically induced; D051379:Mice; D008940:Mitotic Index; D009336:Necrosis / Q000473:pathology; D010578:Petroleum / Q000633:toxicity*; D011083:Polycyclic Compounds / Q000633:toxicity; D011230:Precancerous Conditions / Q000139:chemically induced*; D012867:Skin / Q000187:drug effects* / Q000473:pathology; D012878:Skin Neoplasms / Q000139:chemically induced*; D012883:Skin Ulcer / Q000139:chemically induced
chemical_list: D010578:Petroleum; D011083:Polycyclic Compounds; D003436:Croton Oil