以100μmol·L(-1)亚硫酸氢钠对H9C2心肌细胞染毒不同时间(3,6,12,24 h),采用Wistar大鼠作为模型进行整体动物染毒,SO2组动式吸入SO2(7 mg·m(-3))28 d,每天4 h;SO(2+)NALC(N-乙酰半胱氨酸)组吸入同样条件的SO2,且自SO2染毒之日起隔天腹腔注射50 mg·kg-1(b.w.)NALC,对照组吸入新鲜空气并注射生理盐水.测定大鼠心脏组织和H9C2细胞内ROS含量;采用荧光定量PCR和Western blot分析I型胶原(Col1a1)和III型胶原(Col3a1)的mRNA转录和蛋白表达水平.结果显示SO2及其衍生物引起的氧化应激显著增加了活性氧(ROS)的产生;SO2及其衍生物不能诱导大鼠心脏组织和H9C2细胞中Col1a1和Col3a1 mRNA转录水平的显著改变,但Col1a1和Col3a1的蛋白表达水平显著升高;同时NALC可减少心脏组织中ROS的产生,有效抑制SO2吸入后Col1a1和Col3a1蛋白表达的上升.提示SO2吸入后可能通过产生ROS最终导致胶原蛋白表达的增加.
H9C2 cells were treated with sodium bisulfite for different durations( 3,6,12,and 24 h). Male Wistar rats were exposed to SO2(7 mg·m(-3))for 28 days,4 hours per day in SO2 group. Rats in SO(2+)NALC group were exposed to SO2 and NALC( 50 mg·kg-1(b.w.),i.p.) dissolved in saline every other day. Rats in control group were exposed to filtered air and saline. ROS contents in rat heart and H9C2 cells were assayed using DCFH-DA.Total RNA and protein were isolated for real-time PCR and Western blotting,respectively. The results showed that ROS generation was significantly promoted together with the protein expression increase of Col1a1 and Col3a1,but the mRNA transcription was not changed. NALC reduced ROS contents after SO2 inhalation and inhibited the increase of Col1a1 and Col3a1 protein expression. It was indicated that SO2 and its derivatives could induce the expression of Col1a1 and Col3a1,which might lead to an increase of the total collagen amount. The whole process is related to the production of free radicals.