title: Persistent light reaction: induction in the guinea pig.
abstract: Persistent light reactions similar to those in humans were observed in the study of photoallergenicity of chemicals in guinea pigs. The animals photoinduced with chemicals reacted to long-wavelength ultraviolet (UVA) radiation in the absence of test materials at the challenge stage. The sensitivity of the animals to UVA persisted for more than 1 year. The minimum erythema dose to UVB of animals in the treated group was less than that in the control group. Our investigations indicate that the main factors influencing the elicitation of persistent light reaction were the amount of Freund's complete adjuvant (FCA) used to enhance the allergic response in animals, and the UVA dose at the induction stage. Based on these findings, we have developed a method to make animals persistent light reactors with high frequency. This method consists of 1 intradermal injection of 1.2 ml emulsified FCA, 5 irradiations with 20.4 J/cm2 of UVA, and topical applications of 5% p-aminoethylbenzoate (benzocaine) at the induction stage. We also found that photosensitivity could be induced using FCA and UVA without photosensitizers.
mesh_terms: D010129:4-Aminobenzoic Acid / Q000009:adverse effects; D000818:Animals; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D008297:Male; D009578:Nitrobenzenes / Q000009:adverse effects; D010787:Photosensitivity Disorders / Q000139:chemically induced*; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D009578:Nitrobenzenes; C036077:nitrobenzene; D010129:4-Aminobenzoic Acid