Biomarkers. 1999;4(4):281-9. doi: 10.1080/135475099230813.
Lead intoxication can interfere with haem synthesis and alter the concentration of haem precursors, such as the neurotoxin 5-aminolevulinic acid, in plasma and urine. The relationship between blood lead concentration (PbB), a biomarker of lead exposure, and 5-aminolevulinic acid concentration in urine (ALAU), a biomarker of the early biological effect of lead, was examined in lead-exposed children. ALAU was assayed by chemical derivatization and high performance liquid chromatography with fluorescence detection. The study subjects were 79 children with moderate to high lead exposure recruited from a lead-poisoning prevention clinic. Their urine had been previously analysed for creatinine (CR) concentration and the benzene metabolite trans,trans- muconic acid, and their blood had been analysed for lead. We found that ALAU was not correlated with PbB (Spearman r=0.088, p=0.44), but the ratio ALAU/CR was correlated with PbB (Spearman r=0.22, p=0.054). Creatinine and ALAU concentrations were higher in urine samples collected in the afternoon than those collected in the morning, a finding that is consistent with known diurnal variation. However the ratio ALAU/CR was not different in morning and afternoon urines, supporting the use of creatinine adjustment of ALAU analysis of spot urine samples. In view of the neurotoxic properties of ALA, future validation studies of biomarkers of lead exposure and effect in children should include ALAU or ALAU/CR as potential markers of lead effect.
铅中毒会干扰血红素的合成，并改变血液和尿液中血红素前体（如神经毒素 5-氨基乙酰丙酸）的浓度。本研究旨在探讨血液铅浓度（PbB）作为铅暴露生物标志物与尿液中 5-氨基乙酰丙酸浓度（ALAU）作为铅早期生物效应生物标志物之间的关系。ALAU 通过化学衍生化和高效液相色谱荧光检测进行测定。研究对象为 79 名来自铅中毒预防诊所的中重度铅暴露儿童。这些儿童的尿液之前已用于分析肌酸酐（CR）浓度和苯代谢物反，反-粘康酸，同时对其血液进行了铅分析。结果发现，ALAU 与 PbB 无相关性（Spearman r=0.088，p=0.44），但 ALAU/CR 比值与 PbB 呈正相关（Spearman r=0.22，p=0.054）。下午采集的尿液样本中，ALAU 和 CR 浓度高于上午采集的样本，这一发现与已知的日变化一致。然而，ALAU/CR 比值在早晨和下午尿液中无差异，支持使用肌酐调整 ALAU 分析尿液的点样本。鉴于 ALA 的神经毒性，未来儿童铅暴露和效应生物标志物的验证研究应将 ALAU 或 ALAU/CR 作为铅效应的潜在标志物。
