细胞更新对慢性饮酒大鼠胃黏膜适应性细胞保护的影响

目的: 以低浓度酒精作为弱刺激,通过慢性饮酒的大鼠动物模型,探讨慢性饮酒和大鼠胃粘膜适应性细胞保护作用之间的关系,以及胃粘膜细胞更新的作用.方法: 分别在饮酒不同时程的大鼠胃内灌注2 ml 100%酒精,分析胃粘膜的损伤情况.以流式细胞术、免疫组化和计算机图像处理技术观察大鼠胃粘膜的细胞增殖和凋亡,探讨胃粘膜的细胞更新情况.结果: ①纯酒精可使大鼠的胃体和胃窦出现溃疡和出血,饮用6%(v/v)酒精3～14 d的大鼠这种现象明显减轻,饮用6%(v/v)酒精1 d和28 d的大鼠则无改变.②饮用6%(v/v)酒精3～14 d的大鼠胃粘膜细胞更新加快,而饮酒28 d大鼠胃粘膜细胞凋亡增加,细胞增殖减少.结论: 细胞更新加快是适度低浓度酒精刺激引起的胃粘膜适应性细胞保护作用的重要原因,低浓度酒精刺激超过一定时限可引起胃粘膜萎缩性病变的趋势,使胃粘膜抵抗能力降低.

Effect of gastric mucosa cell turnover on the adaptive cytoprotection in chronic alcohol drinking rat

Aim: To investigate the correlation between the gastric adaptive cytoprotection and the low concentration alcohol intake in a chronic drinking rat model and the effect of chronic ethanol exposures on the cell turnover of the gastric mucosa and its possible role in adaptive cytoprotection. Methods: Sprague-Dawley rats received the drinking water containing 6%(v/v) ethanol as their only water intake for 28 days. In the different stages of the 28 days (1 st, 3 rd, 7 th, 14 th and 28 th days), the stomachs of the rats were cannulated and perfused with pure ethanol, and the severity of mucosal lesions was measured in 2 hours at the end of perfusion respectively. The cell proliferation and apoptosis in gastric mucosa of rats in different groups were analyzed by flow cytometer, immunohistochemistry and computer image analysis. Results: Pure ethanol caused ulcer and haemorrhagic damage in the corpus and antral mucosa of the control rats. These lesions were prevented by pretreatment of the animals with ethanol exposure in the 3 rd to 14 th days. The damage index was decreased by 80%, as compared with those in control rats. There was no significant difference in the rats exposed to the ethanol in the 1 st and 28 th days. Compared with control, the cell apoptosis in gastric mucosa of the rats was enhanced during they exposure to the ethanol in the 3 rd to 28 th days. Otherwise the cell proliferation was increased in the 3 rd to 28 th days,and decreased in the 28 th days, respectively. Conclusion: Chronic adequate alcohol intake may enhance the cell turnover of gastric mucosa and lead to an adaptive cytoprotection. Long-term stimulus with the low concentration ethanol may cause the atrophy of gastric mucosa and reduce the gastric mucosal cytoprotective effect.