The Interchangeability of the Elements Chlorine and Iodine in Culture Media for Human Thyroid Fibroblasts

Abstract

Among those elements which occur only in minor amounts in the human body, none has such an interesting history or has been the subject of so much research as iodine. Although there can be no doubt concerning its physiological significance, actually very little is known about the requirement of various cells and tissues for this element in both its organic and inorganic forms. In view of the fact that the human body not only contains chlorine and iodine, but also fluorine and bromine, the question naturally arises whether all are vital elements and to what extent they can replace one another. The experiments reported in this article were undertaken to determine the interchange-ability of chlorine and iodine in culture media for human thyroid fibroblasts. The effect of iodine and iodides on tissue cultures has been studied by various investigators. Pitini (12) observed a stimulating effect of potassium iodide on the growth of spleen and sciatic nerve of young guinea-pigs. Glass capillaries filled with a 10 per cent solution of the iodide were placed in close proximity to the cultures. In the interpretation of the results obtained with such a method it must be borne in mind that divers uncontrollable factors may affect the tissue growth, such as local changes in the osmotic pressure and in the pH of the culture medium.