The distribution of thallous ion between blood cells and plasma at equilibrium.

We have investigated the distribution of thallous ions between plasma and blood cells in whole blood both in vitro and in vivo (rabbit whole blood) and in vitro (human whole blood). The means of the percentual distribution are within the range of 61.4 to 64.2 percent for cell packet and 35.8 to 38.6 percent for plasma (n = 50), which is in agreement with previous reports. No significant differences between the two species were found when the direct percentages were compared; however, significant differences appeared (p less than 0.01; dose range 1 to 40 micrograms ml-1) when the comparison was made in terms of the ratio:(formula:see text). As for the effect of dose, there is an an apparent disminution in the thallium retained by the cells as the dose increases. However, when the comparison is made in terms of the normalized values, the dose effect is null within the range 1 to 40 micrograms ml(-1). Finally, the observed ratio cell packet/plasma (between 2 and 3) suggests that in whole blood, at equilibrium, thallous ion is mainly distributed passively between cells and plasma. The biological significance of it is discussed.