Study Of Apoptosis Induced By NaAsO₂ And Antagonizes Effect Of Na₂SeO₃ In Human Periphery Blood Lymphocytes In Vitro

Objective :To investigate the different dose sodium arsenite (NaAsO₂) on lymphocyte biological effect and function mechanism,and the antagonism effects of selenium in vitro. Methods :NaAsO₂ and sodium selenite (Na₂SeO₃ )action on the cell growth, apoptosis, periodicity and the expression of relate gene in human lymphocyte in vitro was observed by MTT assays,Hoechest 33258 fluorescence staining, electro microscopy detection, DNA gel electronphores and PI fluorescence flow cytometry (FCM), and immunohistochemical staining. Results: (1)NaAsO₂ and Na₂SeO₃ inhibited the growth of lymphocyte in a dose-dependent manner in a certain range of dose with a IC50 of 8.63μmol/L and 5.12μmol/L; the survival rate of lymphocyte were decreased after NaAsO₂ treatment. 0.5μmol/L Na₂SeO₃ reduced theinhibitory effects of arsenic on lymphocytes proliferation; (2) Characteristic morphologic features of apoptosis were observed in lymphocytes treates with NaAsO2.Under electron microscope,spines on the surface of the lymphocytes decreased, some chromosome gathered at the margin of cell nuclear,The membrane structures of mitochondrion become obscure; (3)DNA ladder were observed in lymphocytes treated with lumol/L NaAsO2 after 48 hours; (4) NaAsCb treatment at O.K 1 .(h 5.0umol/L resulted in a sub-Gicell peak.The decrease of Gi ^ G2 phase cell and the increased percentage of S phase cell were observed by flow cytometer, the cell cycle arrested on S phase.The apoptosis rate were 33.1%^ 38.7%> 50.7%, but the apoptosis rate decreased to 14.0%> 23.4%> 34.4% after add selenium; (5) The expression of bcl-2 decreased than those in contrl group.Conclusions:NaAsC>2 not only can inhibite proliferation but also induce apoptosis of lymphocytes .Some dose of selenium can antagonize the apoptosis induced by arsenic.