Ba2+ ions hyperpolarize algal cell membrane and enhance plasmalemma resistance without affecting ion and water contents.
Culturing the fresh-water alga Hydrodictyon reticulatum for 9 days in the presence of 0.2 and 0.4 mmol/l Ba2+ increases the membrane potential about twice and the plasmalemma resistance 5-10 times without having any significant effect on the cell contents of water and Na+, K+ and Cl- ions. While in control cells the membrane potential is determined by the diffusion potential of K+, in Ba(2+)-treated cells the factor determining membrane potential and resistance is the unequal distribution of protons across the membrane.
Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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R
Metlicka
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Rauferová
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K
Sigler
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K
Janácek
D001464:Barium / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002712:Chlorides / Q000378:metabolism; D000460:Chlorophyta / Q000187:drug effects / Q000502:physiology*; D007477:Ions; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
D002712:Chlorides; D007477:Ions; D001464:Barium; D012964:Sodium; D011188:Potassium