Extracellular calcium is required for the maintenance of plasma membrane integrity in nucleated cells

Cell Calcium. 2005 Jul;38(1):53-7. doi: 10.1016/j.ceca.2005.03.006.


In contrast to rat and human erythrocytes, nucleated erythrocytes from two fish species (Cyprinus carpio and Salmo trutta) underwent almost complete haemolysis in 20 min of EDTA addition. Using Ca2+/Mg2+ EGTA-citrate buffer, we observed that half-maximal haemolysis of fish erythrocytes occurs at [Ca2+]o approximately 10 microM independently of extracellular Mg2+ concentration. Attenuation of [Ca2+]o with EGTA also decreased stability of the plasma membrane of vascular smooth muscle cells (VSMC) and HeLa cells, indicated by a three- to five-fold elevation of lactate dehydrogenase release and passive permeability of plasma membrane for Na+. In VSMC, EGTA lowered [Ca2+]i by approximately 20%. This effect was absent in VSMC-loaded with the intracellular Ca2+ chelator BAPTA. In contrast to EGTA, BAPTA did not affect haemoglobin release from fish erythrocytes and passive permeability for Na+ in VSMC. Viewed collectively, our data show that in nucleated cells, extracellular Ca2+ plays a crucial role in the maintenance of plasma membrane integrity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Cell Membrane / metabolism*
  • Cell Nucleus / metabolism*
  • Egtazic Acid / analogs & derivatives
  • Egtazic Acid / pharmacology
  • Erythrocytes / cytology
  • Erythrocytes / drug effects
  • Erythrocytes / metabolism*
  • Fishes
  • HeLa Cells
  • Hemoglobins / metabolism
  • Hemolysis / drug effects
  • Humans
  • L-Lactate Dehydrogenase / metabolism
  • Magnesium / pharmacology
  • Male
  • Muscle, Smooth, Vascular / cytology
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / metabolism*
  • Rats
  • Rats, Wistar
  • Sodium / metabolism


  • Hemoglobins
  • Egtazic Acid
  • Sodium
  • L-Lactate Dehydrogenase
  • Magnesium
  • 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid
  • Calcium