Uncoupling of an Epithelial Cell Membrane Junction by Calcium-Ion Removal

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Science  07 Jan 1966:
Vol. 151, Issue 3706, pp. 89-91
DOI: 10.1126/science.151.3706.89


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++