Studies on the concentration of radioiodide and thiocyanate by slices of the salivary gland

Abstract

Slices of salivary glands of the mouse concentrate (I131) iodide 5-10 times from the surrounding medium. All the I131 in the gland is present as iodide; no evidence of organic synthesis has been obtained. Concentration of (I131) iodide is inhibited by the addition of perchlorate, thiocynate, iodide and nitrate to the medium, the order of activity being perchlorate > thiocyanate=iodide > nitrate, as in vivo. The amount of endogenous thiocyanate in the gland and plasma is high compared with the amount which has to be added to the medium to inhibit the concentration of (I131) iodide. The addition of 2:4-dinitrophenol to the medium depresses both the respiration of the slices and their concentration of (I131) iodide, indicating that energy is probably necessary for the process of concentration. Evidence is adduced for a possible competitive-adsorption process to explain the mechanism of concentration.