苯暴露尿中苯巯基尿酸的变化

目的 探讨尿苯巯基尿酸(S-phenylmercapturic acid,S-PMA)作为苯职业性暴露生物标志物的可行性.方法 动物模型研究:48只成年SPF级Wistar大鼠,随机分为对照组、低浓度组(4mg/m3)、中浓度组(6 mg/m3)和高浓度组(10 mg/m3),雌雄各半;纯苯动态染毒28 d(4个时段,每个时段染毒5 d后停止2 d).监测苯浓度,每个时段染毒后立即取5 h尿,高效液相色谱-离子阱质谱联用技术检测大鼠尿中S-PMA含量.人群研究:接触组为广州市某船厂80名接触混苯的工人,对照组为该厂40名行政管理人员,对照组除不接触混苯外,其他与接触组均衡可比;检测环境中混苯浓度,收集研究对象班后尿.尿样处理和尿S-PMA检测同鼠尿.结果 (1)动物模型研究:在不同染毒时间内,鼠尿中S-PMA浓度随着环境中苯浓度的增高而升高,低、中、高3组间尿中S-PMA含量的差异有统计学意义(P＜0.01或P＜0.05),但尿中S-PMA含量未随染毒时间延长而变化,同浓度组染毒不同时间,鼠尿中S-PMA含量的差异无统计学意义(P＞0.05).(2)人群研究:接触低浓度混苯的工人尿中S-PMA含量为(13.6±3.4)μg/L,高浓度组为(27.2±7.9)μg/L,两组比较,差异有统计学意义(P＜0.01).大鼠和人群对照组尿中S-PMA本底值均低于5 μg/L.结论 尿中S-PMA含量与环境中苯浓度有关,暴露时间长短对其没有明显影响,在低浓度暴露情况下,尿中仍能检测到S-PMA,可以认为其是反映苯职业接触水平比较敏感的生物标志物.

Urinary S-phenylmercapturic acid variation in benzene exposed

OBJECTIVE: To observe the urinary S-phenylmercapturic acid (S-PMA) variation in the benzene dynamic exposed rat models and benzene exposed workers, and study the feasibility of use of urinary S-PMA as the biomarker in benzene exposed. METHODS: In an animal model study, forty-eight adult Wistar rats were randomly divided into 4 groups: the control group, low-dose group, middle-dose group and high-dose group. The exposed groups were dynamically exposed for 28 days (4 periods) by benzene and the concentration was monitored. The urine was immediately collected after every exposure period and detected by the liquid chromatographic/mass spectrometry methods. In a cohort study, eighty benzene exposed workers in a ship-yard in Guangzhou were selected as the exposed subjects while forty healthy officers in the same shipyard who were not occupationally exposed to benzene were treated as the control. The urine was collected after work shift. The urinary S-PMA and the benzene in the workplace was treated as the rat model. RESULTS: In the animal model study, the urinary S-PMA increased along with the environment benzene in every period and had significantly difference in the different exposed groups (P < 0.01 or P < 0.05), but did not change along with the exposed time course (P > 0.05). In the cohort study, the urinary S-PMA in the high-dose group (27.2 +/- 7.9)microg/L] was significantly higher than the low-dose group (13.6 +/- 3.4)microg/L] (P < 0.01). Otherwise, the background of urinary S-PMA was lower than 5microg/L in both workers and rat models. CONCLUSION: The urinary S-PMA can be proposed as a sensitive biomarker of occupational benzene exposure.