S-phenylcysteine in albumin as a benzene biomarker
- Inhalation Toxicology Research Institute, Albuquerque, NM (United States)
Biological markers of internal dose are useful for improving the extrapolation of health effects from exposures to high levels of toxic air pollutants in animals to low, ambient exposures in humans. Previous results from our laboratory have shown that benzene is metabolized by humans to form the adduct S-phenylcysteine (SPC). Levels of SPC measured in humans occupationally exposed to benzene were increased linearly relative to exposure concentrations ranging from 0 to 23.1 ppm for 8 hr/day, 5 days/week. However, the method of measurement used was laborious, prone to imprecision and interferences, and insufficiently sensitive for the low-dose exposures anticipated in the United States (100 ppb>). An improved chemical method was necessary before SPC adducts in albumin could be used as a benzene biomarker. A simple, sensitive method to measure SPC adducts is being developed and is based on the cleavage of the cysteine sulfhydryl from blood proteins treated with Raney nickel (RN) in deuterium oxide. The product of the reaction with SPC is monodeuterobenzene. SPC treated with RN released monodeuterobenzene in a concentration-dependent fashion. SPC was measured by RN treatment of globin from rats repeatedly exposed by inhalation to 600 ppm benzene. SPC levels measured using the RN approach were 690 {+-} 390 pmol SPC/mg Hb (mean {+-} % difference, n = 2), as opposed to 290 {+-} 45 pmol SPC/mg Hb (mean {+-} SEM, n = 3) as measured by our previous method. This method may facilitate the cost-effective, routine analysis of SPC in large populations of people exposed to ambient levels of benzene. 4 refs., 3 figs.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-76EV01013
- OSTI ID:
- 472152
- Report Number(s):
- CONF-9506288--
- Journal Information:
- Environmental Health Perspectives, Journal Name: Environmental Health Perspectives Journal Issue: Suppl.6 Vol. 104; ISSN 0091-6765; ISSN EVHPAZ
- Country of Publication:
- United States
- Language:
- English
Similar Records
Benzene hemoglobin adducts in mice and rats: Characterization of formation and physiological modeling
Characterization of hemoglobin adduct formation in mice and rats after administration of ( sup 14 C)butadiene or ( sup 14 C)isoprene