RESUMO
OBJECTIVE: To investigate the interaction of occupational vanadium exposure and heat shock protein 70-hom( HSP70-hom) gene polymorphism on the oxidative stress level of workers. METHODS: By judgment sampling,87 workers from vanadium products plant as vanadium exposure group and 63 workers from chemical industry as control group were enrolled into this investigation. The activities of total superoxide dismutase( T-SOD),manganese-containing superoxide dismutase( Mn-SOD),copper and zinc-containing superoxide dismutase( Cu Zn-SOD) and inducible nitric oxide synthase( iNOS),and the level of malondialdehyde( MDA) in the serum of studied subjects were detected. The HSP70-hom genotype was examined by restricted fragment length polymorphism-polymerase chain reaction. Based on the above data,the comprehensive impact of HSP70-hom gene polymorphism and vanadium exposure on workers' oxidative stress level was analyzed. RESULTS: Compared with the control one,the activities of serum T-SOD and Mn-SOD of vanadium-exposed group were significantly decreased( P < 0. 01),while the level of serum MDA was significantly increased( P < 0. 01).Furthermore,the serum T-SOD activity of T / T genotype was statistically lower than that of T / C + C / C genotype( P <0. 01). Both high serum( T-SOD) activity and high MDA level were significantly influenced by the interaction between vanadium exposure and HSP70-hom polymorphism by univariate Logistic regression analysis( P < 0. 05). Using multiple Logistic regression and crossover analysis,multiplicative and additive interactions on high serum( T-SOD) activity between vanadium exposure and HSP70-hom polymorphism was observed [odds ratio( OR) was 6. 051,95% confidence interval( CI) : 1. 001-36. 572,P = 0. 05]and the attributable proportion due to interaction was 0. 935( 95% CI: 0. 086-1. 783).However,high serum MDA level was significantly associated with vanadium exposure [OR( 95% CI) : 6. 352( 3. 099-13. 021),P < 0. 01] without interaction observed. There was no significant effect of vanadium exposure or HSP70-hom polymorphism on either Cu Zn-SOD or iNOS. CONCLUSION: Vanadium exposure might have an impact on the oxidative stress level of the workers by regulating the activity of serum SOD and the level of serum MDA. Besides,vanadium exposure and HSP70-hom polymorphism could interactively interfere with serum T-SOD activity of workers.