ABSTRACT Background: Aquaporins (AQPs), the family of water-selective channels, are localized in various organs and tissues, including the gastrointestinal (GI) tract. However, the roles of AQPs in the GI tract remain unclear. Materials and Methods: Male SD rats were subjected to subtotal colectomy (Group C, n = 22) or a sham operation (Group S, n = 16) and were sacri-ficed on postoperative days 7, 14, and 28. Total RNAs from the distal ileum and rectum were extracted. Quantitative RT-PCR was performed to measure AQP8 mRNA expression. For light-microscopy or immunohistochemistry, paraffin-embedded sections of 4 μm were prepared with H-E staining or anti-AQP8 antibody reaction. Mann-Whitney U-test was performed to compare the AQP8 distributions between the two groups, and the statistical significance was defined as p < 0.05. Results: AQP8 mRNA expression was enhanced in both the ileum and rectum in Group C at day 7. AQP8 protein expression was consistently observed in the ileum and rectum. The villus length in the ileum of Group C was significantly greater than that of Group S at days 7 and 14. Conclusion: Enhanced AQP8 mRNA expression in the subtotal colectomy model suggests that AQP8 plays an important role in maintaining the intestinal fluid balance.
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Nakano, M. , Koyama, Y. , Nogami, H. , Yamamoto, T. and Wakai, T. (2013) Enhanced aquaporin 8 expression after subtotal colectomy in rat. Open Journal of Gastroenterology, 3, 253-258. doi: 10.4236/ojgas.2013.35043.
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