title: Use of dose-response data to compare the skin sensitizing abilities of dicyclohexylmethane-4,4'-diisocyanate and picryl chloride in two animal species.
abstract: Groups of English smooth-haired guinea pigs and BALB/cBy mice were exposed to dicyclohexylmethane-4,4'-diisocyanate (HMDI) and picryl chloride (PiCl) by topical exposure. Guinea pigs were challenged 7 days later by patch testing and responses graded at 24 hr. Application of high doses of each chemical resulted in extensive erythema and a large proportion of animals became sensitized. Lower doses produced less sensitivity. In mice, sensitivity was assessed by extent of ear swelling upon challenge 5 days following the sensitization exposure. In mice, as well as in guinea pigs, a dose-response relationship was apparent between the sensitizing dose and both severity of response and number of animals responding. For mice, comparison of the dose of chemical required to sensitize 50% of the animals (SD50) yielded 0.40 mg/kg for PiCl and approximately 0.20 mg/kg for HMDI. Use of the SD50 should provide a method for assessing the ability of various chemicals to cause contact sensitivity.
mesh_terms: D000005:Abdomen / Q000187:drug effects; D000287:Administration, Topical; D000818:Animals; D003485:Cyanates / Q000633:toxicity*; D003877:Dermatitis, Contact; D004305:Dose-Response Relationship, Drug; D004423:Ear / Q000187:drug effects; D006168:Guinea Pigs; D006968:Hypersensitivity, Delayed; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010853:Picryl Chloride / Q000633:toxicity*; D012882:Skin Tests; D013045:Species Specificity
chemical_list: D003485:Cyanates; C013606:methylene bis(4-cyclohexylisocyanate); D010853:Picryl Chloride