Abstract
In an investigation of the plasma-cell partition of blood lead the following conclusions were reached:
(1) At least 90% of the total blood lead of rabbits is found in the cell fraction after separation of the latter by centrifugation; this applies both to normal animals and to those exposed to large quantities of lead. The same is true in the case of human blood.
(2) It is probably correct to assume that the lead found in the cell fraction after centrifugation of rabbit blood is there by virtue of an actual association with the cells, and not as the result of the formation of a lead compound which settled out with the cells during the centrifugation. If some lead compound of this type is present in blood it is formed only in the presence of the cells, not the plasma alone.
(3) There is no significant difference between the plasma-cell lead partition in arterial blood and that in venous blood.
(4) The use of heparin, potassium oxalate, or sodium citrate does not cause a significant change in the plasma-cell lead partition.
(5) The plasma-cell and the serum-clot partitions of lead in rabbit blood do not differ significantly.
(6) When lead chloride solution is added to the whole blood (heparinized) of normal rabbits most of the lead is taken up by the cells; over 90% of the total lead is found in the cell fraction with lead levels as high as 0.35 mgm. of lead per 100 grams of blood, while at 0.55 mgm. per 100 grams at least 80% of the lead is associated with the cells.
(7) When lead chloride solution is added to the heparinized plasma of the blood of normal rabbits the reactivity of the lead is interfered with in some way by the plasma, so that when the cells are returned to the plasma, their removal of the lead is retarded; 24 hours are needed for the removal of as much as 75% of the total lead.
(8) This reduced ability of the cells to remove lead which has been added to blood plasma is not due to changes suffered by the cells during centrifugation, but is caused by some type of reaction of the lead with the plasma.
(9) These facts indicate that there is a rapid reaction between lead and some constituent of the cells, taking precedence over the reaction that occurs in plasma in the absence of cells. Presumably, the reaction with the cells results in the formation of a more insoluble—or less reactive—compound than that which is formed with the plasma.
Footnotes
- Received August 12, 1942.
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