THE EFFECT OF INORGANIC AND ORGANIC IODIDES UPON THE OUTPUT OF RESPIRATORY TRACT FLUID

Abstract

In an investigation of the reputed expectorant action of iodides, some 300 to 400 rabbits and cats were urethanized and arranged for the collection of respiratory tract fluid (R.T.F.). Potassium iodide and the synthetic, organic iodides Siomine (N.N.R.), and Iod-Ethamine, given by stomach tube, significantly augmented the output of R.T.F. in doses comparable to the recommended human dose. Iodized proteins, such as Iodalbin (N.N.R.) and Iodo-Casein (N.N.R.), and iodized fatty acids or oils, such as Lipoiodine (N.N.R.), Iodo-starine (N.N.R.), Lipiodol (N.N.R.), Oridine (N.N.R.) Stearodine (N.N.R.), Sajodin (N.N.R.), and Iodicin, had no effect upon the volume output of R.T.F., even when given in a wide range of doses. The mechanism of expectorant action was studied with potassium iodide, which, when given to urethanized cats in which the anterior and posterior gastric branches of the vagus nerve had been severed, caused no increase in the output of R.T.F., proving that the expectorant action was by way of a reflex from the stomach, probably up the afferent vagus to the medulla oblongata and then down the efferent vagus to the bronchial glands. No evidence was found that the expectorant action of iodides was due to a direct effect upon the bronchial glands, but after giving potassium iodide and Iod-Ethamine to cats and rabbits, there followed a marked increase in the concentration of iodine-containing compounds in the R.T.F., and this latter may or may not account for the reputed mucus-liquefying effect of iodides.