环氧化酶对大鼠胃黏膜细胞系的保护作用

Protective role of cyclooxygenase on rat gastic mucosa cell line

应用MTT法、DNA条带分析及流式细胞仪分析法比较环氧化酶 (cyclooxygenase) (COX 1和COX 2 )非选择性抑制剂消炎痛和COX 2选择性抑制剂NS 398对大鼠胃黏膜上皮细胞株 (RGM 1)的作用 ,并用Northernblot印迹法分析脂多糖 (LPS)作用于RGM 1后 ,COX 1和COX 2的不同变化。结果发现消炎痛在一定的浓度范围内可诱导RGM 1细胞的凋亡、抑制其增殖 ,并有明显的量效关系 ,而NS 398对RGM 1则无明显作用。若预先用LPS作用于细胞后 ,消炎痛对细胞的作用明显减轻 ,而NS 398的作用无明显变化。Northernblot分析表明 ,LPS作用于细胞后 ,RGM 1细胞COX 2mRNA的水平明显增加。放射免疫分析 (RIA)证实LPS的作用可提高细胞PG的水平。提示 ,COX 1和COX 2在维持胃黏膜细胞的完整性中可能起不同的作用。

MTT assay, flow cytometry assay and DNA ladder assay were used to investigate the effect of cyclooxygenase (COX-1、COX-2) non-selective inhibitor-indomethacin and COX-2 selective inhibitor-NS-398 on rat gastric mucosa cell line(RGM-1), and Northern blot analysis was used to test the change of COX-1 and COX-2 stimulated by lipopolysaccharide(LPS). The results were as follows: Indomethacin induced apoptosis and inhibited proliferation of RGM-1 cells in a dose-dependent manner. No difference was observed in RGM-1 cells when adding NS-398. The damage to the cells was lessened when they were treated with same dose of indomethacin after stimulation with LPS. Northern blot analysis showed that unstimulated RGM-1 cells did not express COX-2 mRNA. However, expression of COX-2 mRNA was enhanced in RGM-1 cells by LPS stimulation. These results demonstrated that COX-1 and COX-2 have different roles in the maintenance of the integrity of gastric mucosa.