Biological exposure indices of pyrrole adducts in serum and urine for hazard assessment of n-hexane exposure

• Published in: PloS one Vol. 9; no. 1; p. e86108
• Main Authors: Yin, Hongyin, Zhang, Chunling, Guo, Ying, Shao, Xiaoying, Zeng, Tao, Zhao, Xiulan, Xie, Keqin
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22.01.2014; Public Library of Science (PLoS)
• Subjects: Adducts; Adult; Alzheimer's disease; Alzheimers disease; Analysis; Animals; Bioindicators; Biology; Biomarkers; Biomarkers - blood; Biomarkers - urine; Biomonitoring; Body Weight - drug effects; Chromatography; Correlation; Correlation analysis; Exposure; Factories; Female; Gait; Gait - drug effects; Hazard assessment; Health care; Hexanes - administration & dosage; Hexanes - adverse effects; Humans; In vitro methods and tests; Laboratory animals; Male; Medicine; Metabolites; Middle Aged; Monte Carlo simulation; n-Hexane; Occupational exposure; Occupational Exposure - adverse effects; Occupational health; Occupational safety and health; Paralysis; Paralysis - etiology; Presynaptic Terminals - drug effects; Proteins; Public health; Pyrroles - blood; Pyrroles - chemistry; Pyrroles - urine; Rats; Studies; Thiophene; Time Factors; Toxicology; Urine; Young Adult; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0086108

Pyrrole adducts might be used as a biomarker for monitoring occupational exposure to n-hexane, but the Biological Exposure Indices of pyrrole adducts in serum and urine are still unknown. The current study was designed to investigate the biological exposure limit of pyrrole adducts for hazard assessment of n-hexane. Male Wistar rats were given daily dose of 500, 1000, 1500, 2000, 4000 mg/kg bw n-hexane by gavage for 24 weeks. The levels of pyrrole adducts in serum and urine were determined at 8, 24 hours postdose once a week. The Biological Exposure Indices was evaluated by neurological evaluation and the levels of pyrrole adducts. The difference in pyrrole adducts formation between humans and rats were estimated by using in vitro test. Dose-dependent effects were observed between the doses of n-hexane and pyrrole adducts in serum and urine, and the levels of pyrrole adduct in serum and urine approached a plateau at week 4. There was a significantly negative correlation between the time to paralysis and the level of pyrrole adducts in serum and urine, while a positive correlation between gait score and levels of pyrrole adducts in serum and urine was observed. In vitro, pyrrole adducts formed in human serum was about two times more than those in rat serum at the same level of 2,5-HD. It was concluded that the BEIs of pyrrole adducts in humans were 23.1 ± 5.91 nmol/ml in serum 8 h postdose, 11.7 ± 2.64 nmol/ml in serum 24 h postdose, 253.8 ± 36.3 nmol/ml in urine 8 h postdose and 54.6 ± 15.42 nmol/ml in urine 24 h postdose.