Voltage-clamp: a useful approach to study in vitro duodenal iron transport in the mouse.
The mechanism(s) controlling iron absorption remain(s) uncertain despite the progress in the identification of genes selectively expressed in the duodenum. The availability of experimental models of iron absorption is critical to the clarification of such mechanism(s). In the present study, a simple method for studying in vitro iron absorption in mouse duodenum is described. Short circuit current, open circuit potentials and epithelial conductances were measured in mouse duodenal segments. Also, unidirectional 55Fe fluxes at different pH conditions were measured in mice with varying iron status. The findings reinforce evidence for an adaptive response of the iron absorptive process according to the body iron status. Significant differences are demonstrated between iron fluxes measured in normal and parenterally iron loaded mice and at acidic compared to neutral pH environment. Also, a significant difference was observed between transepithelial potential measured in duodenum from iron-loaded compared to untreated mice. Advances in the understanding of the mechanism(s) of iron absorption can be brought by the application of voltage-clamp techniques to the electrophysiologic study of iron overload mouse models.