Furan is a liver toxicant and carcinogen in rodents. Although humans are most likely exposed to furan through a variety of sources, the effect of furan exposure on human health is still unknown. In rodents, furan requires metabolism to exert its toxic effects. The initial product of the cytochrome P450 2E1-catalyzed oxidation is a reactive α , β -unsaturated dialdehyde, cis -2-butene-1,4-dial (BDA). BDA is toxic and mutagenic and consequently is considered responsible for the toxic effects of furan. The urinary metabolites of furan in rats are derived from the reaction of BDA with cellular nucleophiles, and precursors to these metabolites are detected in furan-exposed hepatocytes. Many of these precursors are 2-( S -glutathionyl)butanedial-amine cross-links in which the amines are amino acids and polyamines. Because these metabolites are derived from the reaction of BDA with cellular nucleophiles, their levels are a measure of the internal dose of this reactive metabolite. To compare the ability of human hepatocytes to convert furan to the same metabolites as rodent hepatocytes, furan was incubated with cryopreserved human and rodent hepatocytes. A semiquantitative liquid chromatography with tandem mass spectrometry assay was developed for a number of the previously characterized furan metabolites. Qualitative and semiquantitative analysis of the metabolites demonstrated that furan is metabolized in a similar manner in all three species. These results indicate that humans may be susceptible to the toxic effects of furan.
呋喃在啮齿动物中是一种肝毒物和致癌物。尽管人类很可能通过多种途径接触到
呋喃,但
呋喃暴露对人类健康的影响尚不清楚。在啮齿动物中,
呋喃需要经过代谢才能发挥其毒性作用。细胞色素P450 2E1催化的氧化作用的初始产物是一种活性α,β-不饱和二醛,即
顺-2-丁烯-1,4-二醛(B
DA)。B
DA具有毒性和诱变性,因此被认为是导致
呋喃毒性效应的原因。大鼠尿液中的
呋喃代谢物来源于B
DA与细胞亲核体的反应,这些代谢物的前体在
呋喃暴露的肝细胞中被检测到。许多这些前体是2-(S-
谷胱甘肽基)
丁二醛-胺交联物,其中的胺是
氨基酸和
多胺。由于这些代谢物来源于B
DA与细胞亲核体的反应,它们的
水平可以作为这种活性代谢物内部剂量的衡量标准。为了比较人肝细胞与啮齿动物肝细胞将
呋喃转化为相同代谢物的能力,将
呋喃与冷冻保存的人和啮齿动物肝细胞一起孵育。开发了一种半定量的
液相色谱-串联质谱法,用于检测先前鉴定的一些
呋喃代谢物。对这些代谢物的定性和半定量分析表明,
呋喃在所有三种物种中以类似方式被代谢。这些结果表明,人类可能对
呋喃的毒性作用敏感。