The influences of calcium and magnesium ions on the exchange of monovalent cations in Neurospora crassa |
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Authors: | Enrique D Sancho Alonso Rodríguez-Navarro |
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Institution: | Departamento de Microbiología, Escuela Técnica Superior de Ingenieros Agrónomos, 14071 Córdoba, Spain. |
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Abstract: | Low-K+, high-Na+ cells of strain RL21a of Neurospora crassa , in steady state with 25 m M Na+, were used to study K+/Na+ exchanges in the presence or absence of Ca2+ and Mg2+. In the presence of Ca2+ and Mg2+, a low concentration of K+ (0.3 m M ) triggered a rapid exchange, but in the absence of the divalents, a high K+ concentration (30 m M ) was required to initiate the exchange at a rapid rate. In the absence of Ca2+ and Mg2+, K+ uptake did not occur at low K+ concentration, internal K+ did not regulate Na+ influx in the presence of external K+, and the efflux of Na+ proceeded at maximum activity at very low-K+ contents. |
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Keywords: | Ion transport potassium transport sodium transport |
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