Factors controlling the electrolyte and water distribution in the blood

Abstract

In combining the known facts to form an inclusive quantitative expression of the phenomena of electrolyte and water distribution we have assumed for the blood the validity of the following physico-chemical laws:

I. At and near the neutral point all strong alkalies are in the form of salts. At blood reaction therefore the total base may be represented as BP + BA, when BP represents the alkali protein salts, BA the salts bound by the alkali with other negative radicles, chiefly Cl' and HCO_a'.

II. The law of Donnan governing the influence of non-permeating ions on the distribution of permeating ions on the two sides of a membrane holds for the membranes of the blood cells. Donnan's theory has been provided with a sound basis of experimental proof by Donnan, by Proctor and Wilson, and especially by Loeb's recent study on the osomotic and electrical behaviors of protein solutions.

III. The osmotic activity of each solute is proportional to the ratio n : N, of gram molecules of solute to gram molecules of water. The presence of the serum proteins, according to the vapor tension determinations of Neuhausen, does not affect the validity of this ratio as the governing factor of osmotic activity.

On the basis of the assumption that the above laws are valid for blood, mathematical expressions have been derived which indicate the distribution of electrolytes and water between cells and serum, and the manner in which the distribution is affected by changes in P_H (CO₂ tension) and oxygen content. The effect of varying CO₂ tensions has been investigated, and the results have been found to accord with those calculated on the basis of the above assumption.