| Objective: To investigate and compare the effect of transporter OAT on the transport of Cinnabar and other Hg-containing compounds Hg Cl2, Me Hg and Hg S.Methods: 1 The 293 T cells were incubated with low dose(5 μM Hg Cl2 and Me Hg, 200 μM Hg S and Cinnabar), medium dose(10 μM Hg Cl2 and Me Hg, 400 μM Hg S and Cinnabar), and high dose(20 μM Hg Cl2 and Me Hg, 800 μM Hg S and Cinnabar) Hg Cl2, Me Hg, Hg S and Cinnabar. Cell viability was determined by MTT assay after 24 h incubation. Following incubation of the 293 T cells with 10 μM Hg Cl2, Me Hg, Hg S or Cinnabar for 24 h, the cells were collected and the intracellular mercury content was detected by an atomic fluorescence spectrophotometer. 2 Thirty-five adult Kunming mice were divided randomly into five groups, 7 mice per group. Mice were administrated by gavage with distilled water(Control), Hg Cl2(32 mg/kg), Me Hg(2.6 mg/kg) or Cinnabar(Hg S, 300 mg/kg) daily for 44 days. Hg contents were determined by Atomic Fluorescence Spectrometry, and the m RNA expression of renal transporter genes was analyzed by RT-PCR. 3 The control 293 T cells and si OAT1/3 293 T cells were treated with Hg Cl2 or Me Hg at concentrations of 0, 5, 10, 20 or 40 μM, or with Hg S or Cinnabar of at concentrations of 0, 200, 400, 800 or 1600 μM, respectively. Cell viability was detected by MTT analysis after 24 h incubation. The control 293 T cell, si OAT1/3 293 T cell and OAT1/3 overexpressed 293 cells were treated with 10 μM Hg Cl2, Me Hg, Hg S, or Cinnabar, respectively. Cell viability was determined by MTT Assay. Intracellular mercury content was detected after 24 h incubation by an atomic fluorescence spectrophotometer. Results: 1 Compared with Hg Cl2 and Me Hg, the cytotoxicity of Cinnabar and Hg S was lower, with cell viability of high dose Cinnabar and Hg S being 65%, while Me Hg being 40%, Hg Cl2 being 20%. The intracellular mercury content was 600 and 570 fold relative to their controls, for Hg Cl2 and Me Hg, respectively. The intracellular mercury content of Hg S was 8 fold to the control. No significant change was found in the intracellular mercury content in Cinnabar treatment groups in relative to the control. 2 The animal experiments demonstrated that the renal Hg accumulation was 300-fold for Hg Cl2 and 80-fold for Me Hg of the Hg content of the control. No significant difference in Hg accumulation was found in Cinnabar treatment group when compared to the control. Furthermore, the expression of OAT1 was increased 6-fold by Hg Cl2 but was not changed by Me Hg, Hg S or Cinnabar when compared to the control. The expression of OAT3 was increased 60-fold by Hg Cl2, 17-fold by Me Hg and 20-fold by Cinnabar. The expression of OATP4c1 was increased 8-fold by Hg Cl2. Hg Cl2 decreased the expression of OAT2 by 95%, and OATP1a1 by 85%, whereas Me Hg decreased OAT2 50%. The expression of URAT1 was increased 10-fold by Hg Cl2 and 7-fold by Me Hg. 3 The normal 293 T and si OAT1 293 T cells were respectively treated with Hg Cl2, Me Hg, Hg S or Cinnabar at the concentration of 10 μM. The intracellular mercury content after treatment with Hg Cl2 was decreased 40% in si OAT1 293 T cells compared to the control cells. The overexpression of OAT1 resulted in 30% increase in intracellular Hg accumulation caused by incubation with Hg Cl2, but no change by Me Hg, Hg S or Cinnabar, when compared to intracellular Hg content of the control cells. The intracellular mercury content after treatment with Hg Cl2 and Me Hg showed significant differences for compared with si OAT3 293 T cells and overexpression 293 cells, which were no changes by Hg S and Cinnabar.Conclusion: 1 The difference of kidney mercury accumulation on Cinnabar, Hg Cl2, Me Hg and Hg S. 2 The kidney uptake transporter OAT1 and OAT3 regulated the transport of Hg Cl2; Me Hg was regulated by OAT3; Moreover, the present study demonstrated that Cinnabar was not mediated by the uptake transporter OAT1 and OAT3. |
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