代谢
甲醛可能通过吸入、口服或皮肤接触被吸收。它是所有细胞中的基本代谢中间体,在丝氨酸、甘氨酸、甲硫氨酸和胆碱的正常代谢过程中产生,也通过N-、S-和O-甲基化合物的脱甲基作用产生。外源性甲醛通过酶甲醛脱氢酶在最初接触点转化为甲酸盐。甲醛氧化为甲酸盐后,碳原子进一步氧化为二氧化碳,或者通过四氢叶酸依赖的一碳生物合成途径转化为嘌呤、胸腺嘧啶和氨基酸。甲醛不会在体内储存,而是通过尿液(主要作为甲酸)排出,或者被其他细胞分子吸收,或者作为二氧化碳呼出。
Formaldehyde may be absorbed following inhalation, oral, or dermal exposure. It is an essential metabolic intermediate in all cells and is produced during the normal metabolism of serine, glycine, methionine, and choline and also by the demethylation of N-, S-, and O-methyl compounds. Exogenous formaldehyde is metabolized to formate by the enzyme formaldehyde dehydrogenase at the initial site of contact. After oxidation of formaldehyde to formate, the carbon atom is further oxidized to carbon dioxide or incorporated into purines, thymidine, and amino acids via tetrahydrofolatedependent one-carbon biosynthetic pathways. Formaldehyde is not stored in the body and is excreted in the urine (primarily as formic acid), incorporated into other cellular molecules, or exhaled as carbon dioxide. (L962)
来源:Toxin and Toxin Target Database (T3DB)