目的　研究全反式维甲酸对胃粘膜上皮异型增生大鼠胃粘膜上皮细胞凋亡及调控基因(Bcl 2、Fas、ICE)蛋白表达的影响 ,探讨维甲酸治疗胃粘膜癌前病变的作用机制。方法　用N 甲基 N 硝基 N 亚硝基胍 (MNNG)建立大鼠胃粘膜异型增生模型 ,设立空白组、造模组和维甲酸治疗组 ,对大鼠胃粘膜用TUNEL法检测细胞凋亡 ,用免疫组织化学法检测Bcl 2、Fas、ICE蛋白表达水平。结果　空白组、维甲酸治疗组和造模组癌前病变发生率分别为 0、2 6.67%和 73 .3 3 % ,细胞凋亡指数分别为 8.3± 3 .1、7.8± 2 .6和 2 .2± 0 .4 ,Bcl 2蛋白表达率分别为 13 .3 %、3 3 .3 %和 66.7% ,过量表达率分别为6.7%、6.7%和 3 3 .3 % ,治疗组与造模组比较 ,差异有显著性 (P <0 .0 5 ) ,与空白组比较 ,差异无显著性(P >0 .0 5 ) ;Fas蛋白表达率分别为 4 6.7%、4 0 %和 6.7%、过量表达率分别为 13 .3 %、2 6.7%和 13 .3 % ;ICE蛋白表达率分别为 2 0 %、60 %和 13 .3 % ,过量表达率分别为 0、13 .3 %和 6.7%。治疗组与造模组比较 ,表达率均差异有显著性 (P <0 .0 5 ) ,过量表达率比较差异均无显著性 (P >0 .0 5 ) ,与空白组比较 ,差异均无显著性 (P >0 .0 5 )。结论　维甲酸治疗可抑制大鼠胃粘膜Bcl 2基因蛋白的表达 ,促进Fas基因蛋白的表达 Objective To investigate the effect of all-trans retinoic acid on the gastric mucosal epithelial cells apoptosis and the expression of regulatory genes (Bcl 2, Fas and ICE) in gastric dysplasia rats and to explore the mechanism of retinoic acid in the treatment of precancerous lesions of gastric mucosa. Methods The model of gastric mucosal dysplasia was established with N-methyl-N-nitroso-N-nitrosoguanidine (MNNG). The blank group, model group and retinoic acid treatment group were established. The apoptosis of gastric mucosa of rats was detected by TUNEL method Immunohistochemistry was used to detect the expression of Bcl 2, Fas and ICE protein. Results The incidence of precancerous lesion in the blank group, the retinoic acid treatment group and the model group were 0,2 6.67% and 73.33%, respectively, and the apoptotic index was 8.3 ± 3 .1, 7.8 ± 2. 6 and 2 .2 ± 0.4, the expression rates of Bcl 2 protein were 13.3%, 33.3% and 66.7% respectively, the overexpression rates of Bcl 2 protein were 6.7%, 6.7% and 33.3% (P <0.05). There was no significant difference between the two groups (P> 0.05), the expression rates of Fas protein were 4 6.7%, 40% and 6.7%, respectively , The overexpression rates were 13.3%, 6.7% and 13.3%, respectively. ICE protein expression rates were 20%, 60% and 13.3%, respectively. The overexpression rates of ICE were 0,13.3% and 6.7%. There were significant differences in the expression rates between the treatment group and the model group (P <0.05), and no significant differences in over-expression rate between the treatment group and the model group (P> 0.05) Significance (P> 0.05). Conclusion Tretinoin can inhibit the expression of Bcl 2 gene protein and promote the expression of Fas gene protein in rat gastric mucosa