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Coupling of excitation and cessation of cyclosis in Nitella : Role of divalent cations
Author(s) -
Barry William H.
Publication year - 1968
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1040720303
Subject(s) - nitella , divalent , cytoplasmic streaming , chemistry , coupling (piping) , excitation , salt (chemistry) , biophysics , inorganic chemistry , cytoplasm , biochemistry , physics , materials science , biology , organic chemistry , quantum mechanics , metallurgy
The effect of external divalent cation salt solutions upon the association of an action potential and cessation of cytoplasmic streaming in Nitella was studied. Nitella cells remained excitable when immersed in solutions of CaCl 2 , MgCl 2 , BaCl 2 , and SrCl 2 . Cessation of streaming coincident with excitation occurred in solutions of CaCl 2 or SrCl 2 but not in solutions of MgCl 2 or BaCl 2 . In cells exposed to solutions containing mixtures of MgCl 2 and CaCl 2 , or MgCl 2 and SrCl 2 , it was the [Ca]/[Mg] or [Sr]/[Mg] which determined the effect of an action potential upon the rate of streaming, rather than the absolute concentrations Ca ++ or Sr ++ . The implications of these data are discussed with respect to the structure involved in the generation of cytoplasmic streaming and the relation of streaming to other types of biological motion.