Effect of UV Irradiation on Superoxide Dismutase Activities of the Rabbit Skin

Lee, Seung Churl; Chun, Inn Ki; Kim, Young Pio

Abstract

This study was undertaken to know whether the UV-irradiation of the skin causes changes in the superoxide dismutase(SOD) activities. After shaving, the back skin of the rabbit was irradiated with UV light ranging from 280 to 320 nm of wavelengths from Burdick lamb (UV800) in doses of either 0.5, 1.0 or l.5 J/cm2. The skin was removed imrnediately after irradiation and the enzyme activity was assayed by the method of McCord ad Fridovich (xanthine-xanthie oxidase system), One unit of the SOD activity was defined as the amount of the enzyme required to inhibit the rate of reduction of cytochrome c by 50%. The protein content of the enzyme was determined by biuret method. The SOD activity of the skin irradiated with 1.0 J/cm was 7. 78 + 1.62 unit/mg protein(Mean+SD; n=10), significantly higher than that of the control(nonirradiated) group(5.62+1.57 unit/mg protein; n=l0). No significant changes were found in the skins irradiated with 1.5 and 1.5 J/cm. This finding indicates that UV irradiation is capablc of increasing the SOD activitiea in the rabbit skin, and suggests that increased superoxide formed by UV irradiatiun induces the increased SOD activies.