LACK OF CORRELATION BETWEEN SUPPRESSION OF CONTACT HYPERSENSITIVITY BY UV RADIATION AND PHOTOISOMERIZATION OF EPIDERMAL UROCANIC ACID IN THE HAIRLESS MOUSE
| Autor: | Meira Bosnic, Vivienne E. Reeve, Ronald D. Ley, Christa Boehm-Wilcox, R B Cope |
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| Rok vydání: | 1994 |
| Předmět: |
Male
Erythema Ultraviolet Rays Dermatitis Contact Photochemistry Biochemistry Mice chemistry.chemical_compound Edema medicine Animals Irradiation Physical and Theoretical Chemistry Skin Mice Hairless integumentary system Epidermis (botany) Urocanic Acid Dose-Response Relationship Radiation General Medicine medicine.disease Fluorescence Molecular biology Hairless Urocanic acid chemistry Female sense organs medicine.symptom Contact dermatitis |
| Zdroj: | Photochemistry and Photobiology. 60:268-273 |
| ISSN: | 1751-1097 0031-8655 |
| Popis: | The immunological consequences of exposure to UVA (320-400 nm) radiation are unclear. This study describes the relationship between the generation of epidermal cis-urocanic acid and the ability to respond to a contact-sensitizing agent, in hairless mice exposed to different UV radiation sources, which incorporate successively greater short-wavelength cutoff by filtration of the radiation from fluorescent UV tubes. Mice were exposed to these radiation sources at doses systematically varying in UVB radiation content but supplying increasing proportions of UVA radiation. All radiation sources were found to generate approximately 35% cis-urocanic acid in the epidermis, thus normalizing the sources for cis-urocanic acid production. However, only those sources richest in short-wavelength UVB resulted in suppression of the systemic contact hypersensitivity response. These sources also induced the greatest erythema reaction, measured as its edema component, in the exposed skin. A strong correlation was thus demonstrated between the induction of edema and the suppression of contact hypersensitivity, but there appeared to be no correlation between the generation of epidermal cis-urocanic acid and suppression of contact hypersensitivity. The sources richest in UVA content did not result in suppression of contact hypersensitivity; furthermore mice previously irradiated with such UVA-rich sources were refractory to the immunosuppressive action of exogenous cis-urocanic acid. A protective effect of the increased UVA content thus appeared to be inhibiting immunosuppression by the available endogenously generated or exogenously applied cis-urocanic acid. |
| Databáze: | OpenAIRE |
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