Effect of Arsenic Trioxide with Various Concentrations on Dendritic Cells in the Conducting Airways of Asthmatic Mice

Abstract：Objective: To investigate the effect of arsenic trioxide (As2 O3 )with three different concentration groups on the distribution and recruitment of dendritic cells(DCs)in the conducting airways of asthmatic mice. Meth ods: Fifty BALB/c mice were divided into 5 groups at random: control group, asthmatic group, therapeutic groups with low dose( 1 mg/kg), moderate dose ( 5 mg/kg) and high dose ( 10 mg/kg) of As2O3. The immunohistochemistry, scanning electron microscope and computerized image analysis were applied to detect airway DCs, respectively. Results: We demonstrated from the control mice that all intraepitheliai NLDC-145+ DCs throughout the respiratory tree could be ac counted for a network of cells with dendritic cell morphology, and the density of DCs varied from(500 + 50)cells/mm2 ep ithelial surface in the large airways, to(60 ± 10) cells/mm2 epithelial surface in the small airways(P ＜ 0.05). The DCs characteristic of spiny and long processes were impressively observed by the scanning electron microscope. Compared with the control mice, the density, but not the distribution of NLDC-145+ DCs was significantly upregulated in the con ducting airways of asthmatic mice( P ＜ 0.01). Compared with the asthmatic mice, the densities, but not the distributions of NLDC-145+ DCs were significantly down regulated in the conducting airways of the therapeutic groups with three varying concentrations of As2O3 ( P ＜ 0.01) while there were no statistical differences between each other ( P ＞ 0.05).Conclusion: Our findings suggest that it might be an important therapeutic mechanism of As2O3 to downregniate not the distribution but the density of DCs in the conducting airways of asthmatic mice, and low dose of As2O3 has potential val ue in treating asthma.