title: Palmitic acid induces the opening of a Ca2+-dependent pore in the plasma membrane of red blood cells: the possible role of the pore in erythrocyte lysis.
abstract: Earlier we found that in the presence of Ca(2+) palmitic acid (Pal) increases the nonspecific permeability of artificial (planar and liposomal) membranes and causes permeabilization of the inner mitochondrial membrane. An assumption was made that the mechanism of Pal/Ca(2+)-induced membrane permeabilization relates to the Ca(2+)-induced phase separation of Pal and can be considered as formation of fast-tightening lipid pores due to chemotropic phase transition in the lipid bilayer. In this article, we continue studying this pore. We have found that Pal plus Ca(2+) permeabilize the plasma membrane of red blood cells in a dose-dependent manner. The same picture has been revealed for stearic acid (20 μM) but not for myristic and linoleic acids. The Pal-induced permeabilization of erythrocytic membranes can also occur in the presence of Ba(2+) and Mn(2+) (200 μM), but other bivalent cations (200 μM Mg(2+), Sr(2+), Ni(2+), Co(2+)) are relatively ineffective. The formation of Pal/Ca(2+)-induced pores in the erythrocytic membranes has been found to result in the destruction of cells.
authors.affiliation: Institute of Theoretical and Experimental Biophysics RAS, Institutskaya, 3, Pushchino, 142290 Moscow Region, Russia. bekonik@gmail.com
authors.forename: Konstantin N
authors.initials: KN
authors.lastname: Belosludtsev
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Trudovishnikov
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Belosludtseva
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Agafonov
authors.forename: Galina D
authors.initials: GD
authors.lastname: Mironova
mesh_terms: D000818:Animals; D001464:Barium / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism*; D021961:Cell Membrane Structures / Q000378:metabolism*; D002478:Cells, Cultured; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D008345:Manganese / Q000378:metabolism; D019308:Palmitic Acid / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001464:Barium; D019308:Palmitic Acid; D008345:Manganese; D002118:Calcium