组织胺对肠粘膜屏障功能的调节作用研究

Observation of the Modulatiny Effect of Histamine on Intestinal Barrier Function

为探讨组织胺对肠粘膜屏障功能的调节作用 ,采用 Ca Co2细胞单层肠上皮系统 -感染模型 ,将 1×1 0 - 6 mmol/L、1× 1 0 - 7m mol/L 和 1× 1 0 - 8mmol/L 三种不同浓度的组织胺 DMEM细胞培养液分别加入已形成类似肠上皮的 Ca Co2细胞单层系统中 ,和定量的大肠杆菌混合培养。观察侵入细胞的大肠杆菌量 ,并用同样的方法测试组织胺调节作用的时间效应。结果 :经浓度为 1× 1 0 - 6 mm ol/L、1× 1 0 - 7m mol/L和 1× 1 0 - 8mmol/L组织胺液处理过的 Ca Co2细胞液的细菌培养结果分别为 5 2 .5、30 .3和 91 .3个 ,而对照组为 5 36 .2个 ,显示不同浓度的组织胺均能明显减少大肠杆菌进入上皮的数量 (P<0 .0 5 )。观察不同的作用时间段发现 :对照组及组织胺 - DMEM培养0 .5、1 .0、2 .0、4.0和 1 8.0小时后的细菌入侵数分别为 1 0 1 .5、1 35 .5、6 4.0、2 9.5、35 .5和 2 2 .5 5个 ,说明组织胺的作用有其时相性。上述实验结果表明 ,组织胺能增强肠粘膜的屏障功能 。

The model of CaCo2 cell monolayer system has been generally accepted as a standard method for in vitro study of the relationship between the epithelium and microbial invasion. In this study, we set up the model with a simplified method and used it to observe if histamine, which is an important inflammatory factor in gastroenteric tract, can offer some barrier protection from E. coli invasion. After two weeks' routine incubation, the established CaCo2 cells monolayer systems were co cultured with 1×10 -8 mmol/L, 1×10 -7 mmol/L and 1×10 -6 mmol/L histamine DMEM for 2 hours, and with frank DMEM as control for the same length of the time. For observation on time course effect of histamine, the co cultures with 1×10 -6 mmol/L histamine DMEM were kept up for 0.5, 1.0, 2.0, 4.0 and 18.0 hours. Bacterial invasion ws assessed by quantitating the number of E. coli within the coultured epithelial cells. The results showed that histamine significantly inhibited the invasion of E. coli to epithelial cells( P<0.05) . The colony counts in co cultures with 1×10 -7 mmol/L and 1×10 -8 mmol/L histamine DMEM were 52.5, 30.3 and 91.3 respectively, compared with 563 in control group. In the study of the time course effect of histamine, the colony conuts of co culture with histamine DMEM for 0.5, 1.0, 2.0, 4.0 and 18.0 hours were 135.5, 64.0, 29.5, 36.0 and 22.5 respectively. It was concluded that histamine can enhance the protective barrier function of intestinal epithelium against E.coli invasion.