In lieu of an abstract, here is a brief excerpt of the content:

LETTERS TO THE EDITOR Dear Sir: I should like to comment on the paper of Ling and Negendank [1] which criticizes and reinterprets recent evidence for the existence of a "sodium pump." I hope to observe the criterion of "good humor" cautioned in your footnote, which also mentions "controversy," "minority view," "the importance of the sodium-potassium pump," and the "countless experiments supporting it." While these are not exactly the stuffof which good humor is composed, one can at least try. I suppose that we, too, are counted with the minority who have "withheld approval of the pump concept." But surely we are not compelled to tread this sacred ground so gingerly. We have stated that the sodium pump does not exist [2, S]. The first comprehensive review which mentioned the sodium pump in its title was that of Glynn and Karlish [4] of 1975, quoted by Ling and Negendank. Perhaps it was in a mood of sheer high spirits that Glynn and Karlish listed 245 articles in support of the sodium pump and none opposed. Yet Ling's ideas had been around for 25 years; so had ours; so had Troshin's. This field is clearly vacuum sealed. Ling and Negendank have chosen the daunting task of examining in detail a handful of the countless experiments and are to be congratulated on clarifying them. The results of their criticisms seem tobe: (1) the most recent and definitive experiments claiming to supply proof of the sodium pump are of debatable validity and/or interpretation, and (2) the data are more easily explained by Ling's own hypothesis of "association-induction." However, this still leaves countless experiments which have not been examined and are still at large and increasing exponentially. Our own conclusion that ionic pumps have no role in biology was derived more simply, by examining the initial postulates. The sodium-pump hypothesis was advanced (vide Ling and Negendank) in the late thirties when it was found that sodium did not obey the Donnan equilibrium assumed to exist across a cell membrane, while potassium did. To explain this apparent discrepancy, active transport of sodium was invoked. But the discrepancy arose because the Donnan equilibrium is a simplified, ideal, and limiting case of Willard Gibbs's heterogeneous equilibrium. A cell represents a heterogeneous equilibrium, a phase which does not mix freely with its environment, and which should not and cannot be treated as a Donnan equilibrium. Therefore, active transport (the "sodium pump") is based squarely on the cell's failure to obey the wrong law! Indeed the Permission to reprint a letter printed in this section may be obtained only from the author. 164 I Letters to the Editor cell does not conform to the Donnan equilibrium. It can and does conform to the Gibbs equilibrium. The sodium-pump hypothesis is therefore unnecessary, and all its attributes are ad hoc. Cell ionic concentrations are determined not by a variety of energized ionic pumps but by the change in standard chemical potential as a given ion passes from an aqueous environment to the immiscible cellular environment. These values are readily calculated from analytic data on the basis of Gibbs's equations [5]. We assume that every valid experiment is explicable on the basis of Gibbs's Phase Rule and Carnot's principle. It has been pointed out that the sodium pump is a mechanism which, working at zero (or less) efficiency, performs no work [6]; nor is any energy available for its irreversible, uphill task [3]. The thermodynamic status ofsuch a "mechanism" defies description, and it should perhaps just be abandoned forthwith to the tender mercies of Occam's razor. REFERENCES 1.Ling, G. N., and Negendank, W. Perspect. Biol. Med. 23:215-239, 1980. 2.Joseph, N. R.; Engel, M. B.; and Catchpole, H. R.Nature (London) 191:1175-1178, 1961; 203:931-933, 1964; 206:6-11, 1965. 3.Joseph, N. R., and Catchpole, H. R. Trends Biochem. Sci. 3:N64, 1978. 4.Glynn, L, and Karlish, S. J. D. Annu. Rev. Physiol. 37:13, 1975. 5.Joseph, N. R. Comparative Physical Biology. Basel: Karger, 1973. 6.Joseph, N. R. Nature (London) 209:398-399, 1966. Hubert R. Catchpole Medical...

pdf

Share