THE DISTRIBUTION OF IODIDE, THIOCYANATE, BROMIDE AND CHLORIDE IN THE CENTRAL NERVOUS SYSTEM AND SPINAL FLUID

¹ From the Department of Pharmacology, New York University College of Medicine

1. The distribution of iodide, thiocyanate and bromide in the central nervous system has been studied and compared to that of chloride normally present.

2. It was found that these anions distribute in these tissues in the same ratio to chloride as in spinal fluid, whereas in other body tissues they distribute in the same ratio to chloride as in serum.

3. It is concluded that iodide, thiocyanate, bromide and chloride are distributed in the extracellular water of the central nervous system in ionic equilibrium not with serum but with spinal fluid.

4. The similarity in distribution of iodide, thiocyanate, bromide to chloride in the central nervous system makes a selective chemical or physical relationship of these substances to cells improbable, and leaves as yet unexplained the pharmacological action of bromide.

5. It is suggested that the extracellular fluid of the central nervous system has the same relationship to spinal fluid as that of other tissues has to serum, and that spinal fluid would thus be the intermediary through which exchanges between the general circulation and nerve tissue takes place.