Expression and distribution of aquaporin 4 protein in the colon of rats

    WANG Yong, ZHANG Fangª²Xin, LING Xiaoª²Ling, SHI Xiangª²Qun

    1Department of Gastroenterology, 3Department of Neurology, PLA General Hospital, Lanzhou Military Command, Lanzhou 730050, China, 2Department of Geriatrics, First Affiliated Hospital, Lanzhou Medical College, Lanzhou 730000, China

    ¡¾Abstract¡¿ AIM: To study the expression and distribution of aquaporinª²4 (AQP4) in the colon of Spraqueª²Dawly rats. METHODS: Expressions of AQP4 in rat¬ðs both proximal and distal colon were performed by immunohistochemistry and a monoclonal antibody against AQP4. RESULTS: AQP4 protein was present throughout the whole colon. Its expression in proximal colon was greater than that in distal colon and its expression was decreasing from the tip toward base of the villus. AQP4 protein was present at the basolateral membrane of the absorptive cells lining the villus tip of the colon. The intercalated goblet cells was not labeled. CONCLUSION: Positive AQP4 in rat¬ðs colon strongly suggests that this protein function as a pathway for water transport in the epithelium. ......