Relations between saliva arsenic levels and serum arsenic and urinary arsenic of rats after exposed to different levels of sodium arsenite

Objective To investigate the relations between saliva arsenic levels and serum arsenic and urinary arsenic of rats after exposed to different levels of sodium arsenite.Methods Thirty-two SD rats were randomly divided into four groups(8 rats in each group),namely the control group,the low,the medium,and the high doses of sodium arsenite exposure groups.Rats of the control group were given 0.9％ NaCI by gavage,and other three groups were given sodium arsenite of 0.2,2.0,20.0 mg/kg body weight by gavage.All animals were administrated every other day for two weeks,then saliva,blood,urine and tissue organs were collected,organ coefficients were calculated,total arsenic concentrations in blood and urine were detected by Atomic Fluorescence Spectrometry(AFS-230) and total arsenic concentration in saliva was detected by Inductively Coupled Plasma Mass Spectrometer(ICP-MS).Results The weight gain values of rats exposed to sodium arsenite were lower than that of the control group,the difference was statistically significant between the highest dose group[(76.13 ± 17.19)g]and the control group[(103.00 ± 12.31)g,P ＜ 0.05].The liver and kidney organ coefficients in the highest dose group [(3.92 ± 0.54)％,(0.96 ± 0.15)％]were significantly higher than that in the control group[(3.27 ± 0.35)％,(0.76 ± 0.05)％,P ＜ 0.05 or ＜ 0.01].The total arsenic concentrations in saliva[(0.044 ± 0.019),(0.211 ± 0.071),(1.128 ± 0.380)mg/L],blood[(11.832 ± 1.887),(45.032 ± 7.216),(121.839 ± 17.323)mg/L]and urine[(0.138 ± 0.085),(0.874 ± 0.328),(8.843 ± 1.754)mg/L]in the three treatment groups were significantly higher compared with that of the control group [(0.018 ± 0.014),(2.267 ± 0.370),(0.025 ± 0.011)mg/L,all P ＜ 0.05],furthermore,there was a significant difference among the three treatment groups (all P ＜ 0.05).The arsenic contents in saliva were significantly correlated with blood arsenic and urinary arsenic,the correlation coefficient was 0.934 and 0.960,respectively (all P ＜ 0.01).Conclusions High dose of arsenic exposure,with a strong toxicity to liver and kidney,can inhibit the increase of rat body weight.Arsenic dose-response relationship exists in the saliva,and saliva arsenic is significantly correlated with blood arsenic and urinary arsenic,suggesting that salivary arsenic can be used as a new biomarker for assessing human exposure to arsenic. Key words: Arsenites; Arsenic; Saliva; Blood; Urine