紫外线对荒漠沙蜥皮肤形态、蜕皮、脂质过氧化和抗氧化酶的影响

为了提高体温,荒漠沙蜥喜好晒太阳的同时增加了紫外线对其皮肤的损伤。本实验研究了不同的紫外线强度(110、300、500、800mJ/cm2)对荒漠沙蜥皮肤形态、蜕皮、脂质过氧化和抗氧化酶的影响。结果显示:皮肤损伤和丙二醛含量的最高峰发生在暴露紫外线300、500、800mJ/cm2后的96、48、24h;SOD活性的最低峰发生在暴露紫外线110、300、500、800mJ/cm2后的24、48、12h;CAT活性在暴露紫外线后立即抑制,然后恢复提高。CAT活性的高低往往伴随皮肤的损伤程度和蜕皮的发生,这表明紫外线对皮肤的损伤与皮肤的脂质过氧化密切相关,CAT是一种主要的抗氧化酶。皮肤的角质层对保护皮肤免受紫外线的损伤也有重要作用。

Effects of ultraviolet B on epidermal morphology,shedding,lipid peroxide,and antioxidant enzymes in the lizard Phrynocephalus przewalskii(Agamidae)

Lizards Phrynocephalus przewalskii use sunlight to increase their body temperature simultaneously increasing the risk of skin damage by ultraviolet B (UVB) irradiation.We investigated the effects of UVB irradiation (110,300,500 and 800 mJ/cm2,respectively) on epidermal morphology,lipid peroxide,and antioxidant enzymes in their skin.Results showed that the peak of epidermal damage and malondialdehyde (MDA) content occurred 96,48 or 24 h after exposure to 300,500 and 800 mJ/cm2 of UVB radiation,respectively.The lowest superoxide dismutase (SOD) activity occurred 24,48,12 and 12 h after exposure to 110,300,500 and 800 mJ/cm2 of UVB,respectively.Catalase (CAT) activity was inhibited immediately,then gradually recovered and the highest CAT levels accompanied the most serious damage of skin morphology.Later on,CAT activity decreased and then even increased to peak levels above control level,which was accompanied by shedding of the damaged epidermal complex.This indicates that epidermal damage induced by UVB is closely related to lipid peroxidation,where CAT acts as a primary antioxidant enzyme.Moreover,the keratinous layer protects the viable cell layer against UVB damage as well.