We examined the expression of aquaporin (AQP)-1 in monolayers of the rat gastric epithelial cell line RGM1 and investigated the roles AQP1 plays in the epithelial restitution during Wound healing. A round Wound of constant size was produced in the center of a confluent cell monolayer using a rotating Silicon tip. The RGM1 cells expressed AQP1 mRNA. Hg2+ (HgCl2), an inhibitor of AQPs, Suppressed cell migration during wound repair in a concentration-dependent manner. Likewise, cell migration was also impaired in cells in which AQP1 was knocked down by RNA interference, resulting in a marked delay Of Wound healing. The AQP1 knockdown RGM1 cells showed a decrease in the formation of membrane protrusions (lamellipodia) at the leading edge of the Wound as compared with control RGM1 cells. These results suggest for the first time that AQP1 plays a crucial role in gastric epithelial cell Migration during Wound healing. (C) 2009 Elsevier Inc. All rights reserved.