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甲醛是一种化学性能活泼的物质,对基因具有毒性,可诱发大鼠呼吸道癌。它广泛地存在于外界环境、香烟雾、职业性工作、汽油及柴油机废气中,机体内代谢反应及某些药物亦可产生内源性甲醛。接触甲醛的细胞会发生DNA蛋白质交联和DNA单链的断裂。100μM的甲醛在支气管上皮细胞和成纤维细胞中诱发的DNA蛋白质交联频数是大致相同的,并且同甲醛的浓度成正比。这两种细胞交联和去交联的速度也相似。在上皮细胞中500μM甲醛诱发的DNA单链断裂的频数为4.2/10~(10)道尔顿,在成纤维细胞中为3.5/10~(10)道尔顿。实验表明,这两种细胞对X线诱致的DNA单链断裂后的修复能力也不相上下。如先
Formaldehyde is a chemically active substance that is toxic to genes and can cause respiratory cancer in rats. It exists widely in the external environment, cigarette smoke, occupational work, gasoline and diesel exhaust, the body’s metabolic reactions and some drugs can also produce endogenous formaldehyde. Cells exposed to formaldehyde undergo DNA protein cross-linking and DNA single-strand breaks. The frequency of cross-linking of DNA proteins induced by 100 μM formaldehyde in bronchial epithelial cells and fibroblasts is approximately the same and is proportional to the concentration of formaldehyde. The rate at which these two cells crosslink and de-crosslink is similar. The frequency of DNA single-strand breaks induced by 500 [mu] M formaldehyde in epithelial cells ranged from 4.2 / 10 to (10) Daltons and 3.5 / 10 to (10) Daltons in fibroblasts. Experiments show that these two kinds of cells on the X-induced DNA single-strand break repair capacity is also comparable. As before