Reistad R, Rossland O J, Latva-Kala K J, Rasmussen T, Vikse R, Becher G, Alexander J
National Institute of Public Health, Oslo, Norway.
Food Chem Toxicol. 1997 Oct-Nov;35(10-11):945-55. doi: 10.1016/s0278-6915(97)00112-9.
In a search for suitable biomarkers for human dietary exposure to heterocyclic aromatic amines (HAAs), we have investigated the concentrations of three common fried food mutagens in food and urine after consumption of a fried meat meal. In this connection we developed a method for the determination of HAAs and have investigated the common fried red meat HAAs 2-amino-1-methyl-6-phenylimidazo[4,5-beta]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx). Eight volunteers participated in the study, each consuming a meal of fried minced beef patties (295 g), boiled potatoes, and a green salad. Urine was collected for two 12-hr periods prior to and following the meal. HAAs were determined in cooked meat and in untreated and acid hydrolysed urine by a series of liquid/liquid extractions, followed by Blue cotton adsorption and finally by a novel derivatized technique for gas chromatography-mass spectrometry (GC-MS). The primary amino groups were derivatized by acylation with heptafluorobutyric acid anhydride, and the resulting amide methylated using diazomethane. Phenolic hydroxyl groups were also methylated by this procedure, making it possible to detect hydroxylated HAAs, possible metabolites or constituents of the fried meat. 4'-Hydroxy-PhIP ¿2-amino-1-methyl-6-(4-hydroxyphenyl)imidazo[4,5-beta]pyridine¿ (4'-OH-PhIP) was indeed found in meat as well as in urine. The contents of PhIP, MeIQx and DiMeIQx in meat were 4.0 +/- 2.6, 3.5 +/- 0.9 and 0.3 +/- 0.1 ng g-1 (mean +/- SD, n = 4), from which the mean amounts ingested were calculated to be 1180, 1030 and 90 ng, respectively. Total amounts of HAAs in the 0-24-hr post-meal untreated urine (and percent of ingested dose) were 6-23 ng PhIP (0.5-2%) and 10-63 ng MeIQx (1-6%). In hydrolysed urine, the levels of HAAs were higher, totalling 24-100 ng PhIP (2-8.5%) and 133-329 ng of MeIQx (13-32%). DiMeIQx was below detection limit in all urine samples. Judged from our study, there were rather large inter-individual variations in the amounts of excreted HAAs, possibly caused by variations in the activities of enzymes taking part in HAA metabolism.
为寻找适用于衡量人体膳食中杂环胺（HAA）暴露量的生物标志物，我们研究了食用煎肉餐后食物和尿液中三种常见油炸食品诱变剂的浓度。为此，我们开发了一种测定HAA的方法，并研究了常见的油炸红肉HAA，即2-氨基-1-甲基-6-苯基咪唑并[4,5-β]吡啶（PhIP）、2-氨基-3,8-二甲基咪唑并[4,5-f]喹喔啉（MeIQx）和2-氨基-3,4,8-三甲基咪唑并[4,5-f]喹喔啉（DiMeIQx）。八名志愿者参与了该研究，每人食用一顿煎牛肉末饼（295克）、煮土豆和一份蔬菜沙拉。在进餐前后各两个12小时时间段收集尿液。通过一系列液-液萃取，接着进行蓝棉吸附，最后采用一种新的衍生化技术用于气相色谱-质谱联用（GC-MS），测定熟肉以及未处理和酸水解尿液中的HAA。伯氨基通过用七氟丁酸酐酰化进行衍生化，所得酰胺用重氮甲烷甲基化。酚羟基也通过此程序甲基化，从而能够检测羟基化的HAA、油炸肉可能的代谢产物或成分。在肉和尿液中确实发现了4'-羟基-PhIP（2-氨基-1-甲基-6-(4-羟基苯基)咪唑并[4,5-β]吡啶）（4'-OH-PhIP）。肉中PhIP、MeIQx和DiMeIQx的含量分别为4.0±2.6、3.5±0.9和0.3±0.1纳克/克（平均值±标准差，n = 4），据此计算出平均摄入量分别为1180、1030和90纳克。餐后0至24小时未处理尿液中HAA的总量（以及摄入剂量的百分比）为6至23纳克PhIP（0.5至2%）和10至63纳克MeIQx（1至6%）。在水解尿液中，HAA水平较高，PhIP总量为24至100纳克（2至8.5%），MeIQx为133至329纳克（13至32%）。所有尿液样本中DiMeIQx均低于检测限。从我们的研究判断，排泄的HAA量存在相当大的个体差异，这可能是由参与HAA代谢的酶活性差异所致。
