Interaction of benzo [A] pyrene and a hyperplastic agent in epidermal nuclear enlargement in the mouse. A dose response study.
Experiments were conducted on the effects of various dose levels of benzo [a]pyrene (BP) on nuclear size in mouse interfollicular epidermis over a 3-day period. Topical application of BP was made with or without croton oil (CO) (0.1 or 0.5%) in the vehicles acetone, toluene and methyl ethyl ketone (MEK). Nuclear size was measured on histological sections either manually or by Quantimet Image Analyser. Vehicle controls treated with 0.1 or 0.5% CO in acetone or MEK gave rise to epidermal hyperplasia with some nuclear enlargement and toluene without CO produced a similar response. It was found that when BP was applied in a vehicle capable of inducing hyperplasia, the nuclear enlargement produced was greater than that produced by either the vehicle control or BP in a non-irritant vehicle. The enhancement of response to BP when tested in the presence of a hyperplastic agent resulted in lower concentrations of BP being detectable. As the levels of BP detectable by nuclear enlargement under these conditions compared reasonably well with those detectable in long-term tests, this system might be usable as a basis for a short-term test for carcinogens.
D000818:Animals; D001580:Benzopyrenes / Q000494:pharmacology*; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure*; D003436:Croton Oil / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006965:Hyperplasia; D051379:Mice; D012867:Skin / Q000187:drug effects / Q000473:pathology*
D001580:Benzopyrenes; D003436:Croton Oil