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Variations in the Erythrocyte Potassium and Sodium in the Possum, Trichosurus vulpecula


THE ratio of the concentration of sodium ions to that of potassium ions in erythrocytes has been recorded for numerous animal species. In most cases, the relation between the concentrations of sodium and potassium is of the same order for individuals of any one species1. This uniformity between individuals, however, does not exist in sheep. Evans2 has summarized the previous work on sheep, and his own results show three distinct types of sheep, according to the concentrations of potassium and sodium in the erythrocytes, in the various breeds he examined. Evans and King3 had already shown that variations in concentrations of these ions in sheep erythrocytes were determined by a single-gene substitution.

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  1. 1

    Kerr, S. E., J. Biol. Chem., 117, 227 (1937). Denton, D. A., Wynn, V., McDonald, I. R., and Simon, S., Acta Med. Scand., 140, Supp. 261 (1951).

  2. 2

    Evans, J. V., J. Physiol., 136, 41 (1957).

  3. 3

    Evans, J. V., and King, J. W. B., Nature, 176, 171 (1955).

  4. 4

    Harris, H., and Warren, F. L., Biochem. J., 60, xxix (1955).

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