Observations on the theory of tetany.

Abstract

It has been found that in the sea urchin egg within certain time limits isotonic solutions of sodium phosphate at various [H⁺], inhibit cell division only by the limiting effect of the hydrogen ion concentration of the external solution. By direct analysis of the eggs it has been shown that within limits the PO₄ = anion does not penetrate.

Eggs treated with isotonic phosphate over a wide hydrogen ion range, subsequently placed in isotonic electrolytes, and finally placed in sea water to determine their viability, show that (1) KCl has practically no injurious effect, (2) NaCl is most toxic with the peak of minimum toxicity at 7.4-7.8, (3) CaCl₂ is toxic with the minimum peak at 7.8, (4) MgCl₂ has relatively little toxicity but markedly shifts the peak towards the alkaline side.

CaCl₂ and MgCl₂ are remarkable in that eggs removed from the ovaries and placed directly into isotonic solutions of these salts even on the most vigorous washing and centrifuging do not cytolyse while the same eggs if allowed to stand in sea water for 1/2 hour or over, agglutinate and cytolyse immediately. Dr. Heilbrunn 1 has independently confirmed this point. This very extraordinary change is of interest from the point of view of the theory of agglutination and ageing.