Non-specificity of the Divalent Cation Capable of Restoring Normal Intestinal Permeability after Chelation Depletion. ∗

Summary and conclusions

1. All of the alkaline earth cations are able to restore normal aqueous permeability of the mucosal epithelial membrane following chelation depletion by Na₂H₂EDTA. 2. Each alkaline earth metal is capable of permeability reinstatement at a minimal concentration. These minimum levels of replacement for each ion are in accord with the position of the elements in the periodic table. 3. The relationship between minimal replacement concentration and charge density appears to indicate that a physical property of these ions is involved in the restoration of permeability, as opposed to a specific biochemical characteristic of a particular ionic species. 4. The particular alkaline earth metal, or combinations thereof, physiologically responsible for regulation of permeability and cell adhesion in epithelial tissue cannot be specified with any degree of certainty.