Biological half-life of bromide in the rat depends primarily on the magnitude of sodium intake.

The parallel course of the excretion rates of bromide and sodium ions was demonstrated in adult male and female rats administered simultaneously with potassium 82Br-bromide and 24Na-sodium chloride. The animals were exposed to various intakes of sodium ions accompanied with five different anions: Br-, Cl-, HCO3-, ClO4-, and SCN-. Regardless of the anion accompanying the sodium ion, the excretion rates of 82Br- and 24Na+ ions were proportional to the magnitude of sodium intake in the animals. Hence, we have proved our hypothesis that the biological half-life of bromide depends on the magnitude of sodium intake rather than on the intake of chloride.