[Effect of N, N-dimethylformamide on oxidation or antioxidation status among occupational exposed workers]

To explore the effect of N,N-dimethylformamide (DMF) on oxidation or antioxidation status among occupational exposed workers.

A total of 104 DMF exposed workers and 101 controls were recruited in this study in May 2012. The information of occupational history, age, gender, smoking and alcohol habits of all subjects were collected by questionnaire. DMF concentration in the air of workplace was tested. N-methyl-carbamoylated haemoglobin adduct (NMHb) in blood was chosen as an inner-dose biomarker, which was expressed as 3-methyl-5-isopropylhydantoin(MVH), the degeneration product of NMHb. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) levels were detected to reflect liver function. Serum superoxide dismutase (SOD) activity, glutathione-S-transferase (GST) activity, malondialdehyde (MDA) levels, 3- nitrotyrosine (3-NT) levels were detected to reflect oxidative/antioxidative status.

DMF concentration in workplace air was within the range of 3.3-12.4 mg/m(3), which did not exceed our national standard. The MVH level in exposed workers was (19.69 ± 12.52) mg/kg, but was not detectable in control group. The activity of SOD in exposed workers ((125.30 ± 21.23) U/ml) was significantly higher than the control group ((118.35 ± 18.48) U/ml, t = -2.47, P = 0.014). However, the activity of SOD showed different trends with the increasing of MVH level. When MVH ≤ 24 mg/kg, the SOD activity increased with the increasing of MVH level (r = 0.356, P = 0.002). However, when MVH> 24 mg/kg, SOD activity expressed decreasing trend with the increasing of MVH level (r = -0.260, P = 0.150). No significant differences were observed in GST, MDA, 3-NT, ALT, AST levels among the two groups.

DMF exposure might have stimulatory effect on antioxidation system of the body under low concentration; within the range of compensatory defense, DMF exposure did not cause obvious lipid and/or protein peroxidative damage.