Aquaporin water channels in gastrointestinal physiology

摘要: Fluid transport is a major function of the gastrointestinal (GI) tract with more than 9 litres fluid being absorbed or secreted across epithelia in human salivary gland, stomach, hepatobiliary tract, pancreas, small intestine and colon. This review evaluates evidence that aquaporin-type water channels are involved GI transport. The aquaporins family (≈30 kDa) integral membrane proteins as channels. At least seven expressed various tissues tract: AQP1 intrahepatic cholangiocytes, AQP4 gastric parietal cells, AQP3 colonic surface epithelium, AQP5 AQP7 intestine, AQP8 liver, pancreas colon, AQP9 liver. There functional data suggesting some cell types expressing have high regulated permeability; however, there has been no direct for role physiology. Recently, transgenic mice generated selective deletions aquaporins. Preliminary evaluation suggests dietary fat processing absorption. Further study aquaporin should provide new insights into normal physiology disease mechanisms, may yield novel therapies to regulate movement diseases.