Distribution, migration and binding of whole blood fluoride evaluated with radiofluoride

Abstract

A study of the distribution of radiofluoride, between the plasma and erythrocytes of dogs' whole blood showed three-quarters of the radiofluoride in the plasma. The distribution was influenced by carbon dioxide tension associated with the pH of the whole blood. Radiofluoride migrated from plasma to erythrocytes as did chloride when the CO2 tension was increased. Less than 5% of the plasma radiofluoride was bound to plasma solutes under physiological conditions. Radiofluoride binding by bovine plasma albumin was increased by increasing the calcium ion concentration and also by increasing the pH of the solution. The binding of radiofluoride to bovine albumin was affected by the calcium ion concentration. In the synthetic plasma at pH 7.4 the albumin restricted filtration of nearly 40% of the radiofluoride when the calcium ion was elevated to 15 mEq/l. At a calcium ion concentration of 5 mEq/l. the bovine albumin apparently bound 15% of the added radiofluoride. If the albumin were not present there was no restriction of radiofluoride filtration by calcium ion. At pH 6.8 calcium ion concentration of 15 mEq/l. restricted only 3% of the radiofluoride and 5 mEq/l. of calcium had no effect.