Objective:To define the localization of aquaporin-4(AQP4)and its mRNA expression in the pancreas.So as to pro- vide morphological basis for the secretory function and regulation mechanisms in the pancreas.Methods:Immunohistochemical (IHC)and in situ hybridization(ISH)staining techniques were used to evaluate the expression of AQP4 and mRNA expression in pancreas.Results:IHC showed that AQP4 and its mRNA were expressed in the membrane of pancreas islet cells;however light-coloured was expressed in the acinus cell.Conclusion:AQP4 might contribute to the precise regulation of water and ion balance in pancreas islet cells

which may be fluctuated during the process of synthesis and secretion of endocrine

but AQP4 might have little contribution to the secretion of pancreatin.