Punnonen K, Jansén C T, Puntala A, Ahotupa M
Department of Dermatology, University of Turku, Finland.
J Invest Dermatol. 1991 Feb;96(2):255-9. doi: 10.1111/1523-1747.ep12462271.
Human Keratinocytes (NCTC 2544) in culture were exposed to either plain ultraviolet A (UVA) irradiation or to 8-methoxypsoralen plus UVA (PUVA) treatment. Lipid peroxidation, activities of antioxidant enzymes, and percentage amounts of 14C-arachidonic acid in various cellular lipid subclasses and in the culture medium were measured. Both UVA irradiation and PUVA treatment induced significant changes in the distribution of arachidonic acid and increased the liberation of arachidonic acid from membrane phospholipids. At 24 h after either UVA irradiation or PUVA treatment the formation of thiobarbituric acid reactive material was significantly increased, whereas the amount of conjugated dienes was unaffected. The activities of the antioxidant enzymes, catalase and superoxide dismutase, were already significantly decreased at 0.5 h after UVA irradiation or PUVA treatment. The enzyme activities were partially restored during the following 24 h incubation. From the present study, we suggest that in keratinocytes both plain UVA irradiation and PUVA treatment induce changes in the distribution of membrane fatty acids and cause an impairment in the enzymic defense system against oxidative stress.
将培养的人角质形成细胞（NCTC 2544）暴露于单纯的紫外线A（UVA）照射或8-甲氧基补骨脂素加UVA（PUVA）处理。测量脂质过氧化、抗氧化酶活性以及各种细胞脂质亚类和培养基中14C-花生四烯酸的百分比含量。UVA照射和PUVA处理均诱导花生四烯酸分布发生显著变化，并增加花生四烯酸从膜磷脂中的释放。在UVA照射或PUVA处理后24小时，硫代巴比妥酸反应性物质的形成显著增加，而共轭二烯的量未受影响。抗氧化酶过氧化氢酶和超氧化物歧化酶的活性在UVA照射或PUVA处理后0.5小时就已显著降低。在随后24小时的孵育过程中，酶活性部分恢复。从本研究中，我们认为在角质形成细胞中，单纯的UVA照射和PUVA处理均会诱导膜脂肪酸分布的变化，并导致对抗氧化应激的酶防御系统受损。
