水通道蛋白-4在大鼠消化器官的表达与分布

Expression and distribution of aquaporins-4 in digestive organs of sprague-dawley rat

目的探讨水通道蛋白-4在SD大鼠消化器官的表达与分布。方法动物麻醉处死后取胃、空肠、回肠、结肠、直肠、胰腺和肝脏等器官,常规进行脱水、固定、石蜡包埋、切片(4μm)后以链酶亲和素-生物素-过氧化物酶复合物法(SABC)检测水通道蛋白-4蛋白在上述组织中的表达。结果AQP4在正常SD大鼠消化道中的表达和分布具有选择性:食管和胃的上部基本不表达AQP4。从胃的中下部始见表达AQP4,集中于深部粘膜的基底部腺体。胃腺表达AQP4的细胞类型为壁细胞。十二指肠、空肠和回肠富含AQP4,但少于胃部,AQP4在十二指肠、空肠和回肠出现的位置主要粘膜深部的腺隐窝。近端结肠的局部腺隐窝可见少量AQP4表达,远端结肠和直肠组未见AQP4表达。胰脏和肝胆亦可见微量AQP4表达。结论SD大鼠下段胃和小肠是AQP4主要表达的部位,近端结肠、肝胆和胰腺只微量表达AQP4。研究消化系统的疾病与AQP4的关系可能有助于我们进一步认识疾病的发病机制。

Objective To describe expression and distribution of aquaporins-4 in digestive organs of sprague-dawley rat. Methods The normal tissue （stomach,ejunum,ileum,colon, rectum,liver and pancrease） from S-D rat were cryosectioned onto microscope slide. Expression of AQP4 was determined by immunohistochemical analysis. Results By immunohistochemistry, AQP4 was localized on the baso-lateral membranes of the parietal cells in oxyntic glands of the lower stomach, but not in the chief cells. The basolateral membranes of the crypt cells in the small intestine （from jejunum to ileum） which were present at the bottom of the crypts were labeled with the anti-AQP4 antibody. No or negligible immu- nostaining for AQP4 was detectable in the esophagus and the upper portion of the stomach. Slight expression for AQP4 was found in the proximal colon, pancrease and liver. Conclusions Lower stomach and small intestine are the main digestive organs for expression of AQP4. These findings may indicate that water crosses the epithelial layer through these water channels, conduceting a possible role of digestive disease.