Comment on: Cloning and characterization of porcine aquaporin 1 water channel expressed extensively in the gastrointestinal system

Figure 3 Model of water and small solute transport across the absorptive epithelium of the human small intestine[21]. The potential routes for water entry into the enterocyte from the luminal (apical) side are AQP10 and the sodium/glucose co-transporter SGLT1. SGLT1 is a secondary active transporter driven by the function of basolateral Na,K-ATPase which co-transports Na+ and glucose along with water into enterocytes. AQP8 (shown in parentheses) has been shown to be located in the sub-apical cytoplasm of absorptive epithelial cells. The basolateral water exit pathway is most likely to be the AQP3 protein[10,27]. Although the location of the AQP7 protein has not yet been precisely determined, it may be involved in glycerol transport in the intestinal lacteal system.