| EFFECT OF SODIUM PARA-AMINOSALICYLIC ON THE CHANGES OF THYROID FUNCTION IN LEAD-EXPOSED RATSObjective To explore the effects of sodium para-aminosalicylate (PAS-Na) on thyroid function disorders of weaning SD rats induced by lead (Pb).Methods A total of 50 weaning SD rats, which included half males and half females, were randomly divided into 5 groups according to indivdual weight:the control group, Pb-exposed group, low, medium and high doses PAS-Na (L-, M-, and H-PAS) groups. The rats of Pb-exposed, L-, M-and H-PAS groups were intraperitoneally given 15mg/kg leadacetate daily for 2 weeks, while others were injected intraperitoneally (i.p.) with the same volume of saline. And then, rats of L-, M-and H-PAS groups were treated with PAS-Na at 100,200 or 300mg/kg by subcutaneous injection (s.c.) in the back for 21 days, while the control group and Pb-exposed group were treated with the same volume of saline. At the end of treatment, all rats were enthanasia. Blood samples were collected from abdominal aortic, femur were collected with all adherent soft tissue removed. GFAAS was used for the detection of blood Pb. Immunoassay system was used for detection of triiodothyronine (T3), thyroxine (T4) and TSH. Morris Water Maze (MWM) was used to test the ability of learning and memory. All data were analyzed using SPSS 16.0 statistical software.Results Intoxication level was defined as blood lead level (BLL)≥100μg/L The mean BLL of Pb-exposed group was 289.7±23.5μg/L. The result of MWM showed that the escape latency and swimming distance were longer in Pb-exposed group then that in control group, but the number of piercings was reduced.BLL had a possitive correlation with the content of TSH in Pb-exposed group (P<0.05). In the control group and H-PAS group, bone lead level had a possitive correlation with the content of T3 (P<0.01～0.05).Conclusion Pb-exposure may have an effect on the content of T3and TSH, which may induce thyroid disorder, and PAS-Na may have an effect on the changes of thyroid function in weaning SD rats.EFFECTS OF LEAD EXOPSURE ON THE THYROID FUNCTION OF CHILDRENObjective Our study aimed to assess the distribution of blood lead level and its relationship to thyroid function of children in a lead-zinc ore district of Guangxi.Methods A total of 249 children(contained 124 boys and 125 girls)were recruited from an elementary school in a lead-zinc ore district of Guangxi Province. A volume of 1ml fasting venous blood of each child was collected and mixed with sodium heparin anticoagulant tube, and stored at-20 °C until assay.A volume of 2ml fasting venous blood was collected with coagulation promoting vacuum tube, and centrifuged at 2000r/mm for 15 min at 4°C. The supernatant was collected and stored at-80 °C until assay. Blood lead level(BLL) was detected by Graphite furnace atomic absorption spectrometry(GFAAS) method.Immunoassay system was used for detection of free triiodothyronine(FT3), free thyroxine(FT4) and thyroid stimulating hormone(TSH). A number of 11 rice samples were randomely collected and the lead level were detected with GFAAS.All data were analyzed using SPSS 16.0 statistical software.Results The mean level of lead in collected rice was 0.16(0.047?0.526)mg/kg. According to the standard level in GB2762-2012, the rate of rice with elevated lead was 18.2%,. Intoxication level was defined as blood lead level(BLL)>100ng/L. The overall mean BLL of children(Mean 土SD) was 94.2土46.6|uig/L(boys: 94.8±42.7|ig/L,girls: 93.7±50.4). The prevalence of children withBLL>100^g/L was 30.9%(boys: 35.5%, girls:26.4%).BLL of boys aged 9 years was lower than that of boys aged 8 years, BLL of girls aged 9 and 11 years was lower than that of girls aged 7 years, BLL of children aged 9 years was lower than that of children aged 8 years(P<0.05). No significant difference was found in children’s prevalence of lead poisoning between different gender and age groups. The TSH content of children with BLL >100|j,g/L was higher than that of children with BLL < lOOfxg/L(P<0.05). A negtive correlation between BLL and the content of TSH was found(P<0.05).Conclusion Lead exposure is still exist in this lead-zinc ore district.Lead poisoning may have an effect on the content of TSH, which could induce thyroid disorder in children.
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