Development of the mucosal barrier: bacterial toxin interaction with the immature enterocyte

The microvillus surface of the enterocyte has been studied extensively to determine if compositional differences in pre- and postweaned animals can account for the increased incidence of immunologic and infectious intestinal disease states in newborns. The interaction of cholera toxin with the developing enterocyte was studied with respect to receptor-effector response. In previous studies, we have reported that more toxin binds to the preweaned animal gut than to the postweaned. More recently we have shown that toxin causes an increased cAMP response and decreased Na+-K1+ATPase response, suggesting that the enhanced response to toxin by the immature enterocyte may contribute to increased toxigenic diarrhea in newborns.