title: Uncoupling of an epithelial cell membrane junction by calcium-ion removal.
abstract: Calcium takes part in maintaining ion communication between salivary gland cells (Chironomus thummi). Its withdrawal from the cell systems results in virtual disconnection of ion communication, at Ca(++) concentrations which do not noticeably affect cell adhesion. The junctional membrane surfaces. which are normally quite freely permeable to ions, become as impermeable as the nonjunctional membrane surfaces; each cell seals itself off irreversibly as a unit. In maintaining ion communication Mg(++) substitutes for Ca(++)
mesh_terms: D000818:Animals; D002118:Calcium; D002463:Cell Membrane Permeability; D002614:Chelating Agents / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D004848:Epithelium / Q000502:physiology*; D066298:In Vitro Techniques; D007477:Ions; D008274:Magnesium; D008925:Mites
chemical_list: D002614:Chelating Agents; D007477:Ions; D004492:Edetic Acid; D008274:Magnesium; D002118:Calcium