Diffusion of Phosphate Ions into Blood Corpuscles

Abstract

WE find on shaking labelled (radioactive) sodium phosphate of negligible weight with blood, that phosphate ions quickly enter the erythrocytes. In the course of three hours, nearly half the phosphate ions present in the plasma of rabbit's blood diffuses into the corpuscles. When labelled phosphate ion enters the cell, it becomes available for esterification processes. Simultaneously, non-labelled phosphoric acid-ester molecules decompose, producing non-labelled phosphate which diffuses into the plasma ; this process is going on incessantly. There is thus a rapid interchange of phosphorus atoms between plasma and cells. In in vivo experiments, using a newly developed technique¹, we find the same rate of penetration of phosphate ions into corpuscles as occurs in vitro. In both cases, not all the acid-soluble organic phosphorus compounds exchange their phosphorus for the labelled variety, and it is of interest to note that a large part of the phosphorus esters which resist hydrolysis when heated for an hour at 100° with mineral acids do not become labelled in the course of a few hours.