In Vivo Analysis of UV-B Induced Photooxidations.
NIOSH 1982 Apr:768-771
Attempts were made to clarify the initial photochemical mechanism by which ultraviolet-B (UV-B) irradiation acts in-vivo. The knowledge already gained of the photochemical and oxidative reactions of cholesterol were used in accomplishing this objective. The Skh-hr-1- hairless-mouse was used as the test system to evaluate the primary process of UV-B photooxidation in-vivo. The animals were injected with tritium labeled mevalonic-acid to produce radioactive cholesterol in-vivo. Injections were made 1 hour prior to irradiation. The major radioactive lipid expected to be formed was cholesterol. Preliminary experiments indicated that ultraviolet irradiation resulted in the formation of a compound or compounds more polar than cholesterol. Products which were expected to be formed other than hydroperoxides were to be investigated in future studies. This included cholesterol-5,6-epoxide and its product, 3beta,5alpha,6beta-trihydroxycholesterol. Studies will also be extended to the Skh-crh-mouse strain which has a low incidence of UV- B induced skin tumors.
Laboratory-animals; Ultraviolet-radiation; Radiation-exposure; Skin-exposure; Carcinogenesis; Metabolic-study; Photochemical-reactions; Nonionizing-radiation;
Proceedings of the Second NCI/EPA/NIOSH Collaborative Workshop: Progress on Joint Environmental and Occupational Cancer Studies, September 9-11, 1981, Rockville, Maryland