METABOLISM OF FLUORINE Absorption, Retention, Distribution and Elimination of Fluorine, and Its Effect on the Vitamin C Content of Different Tissues, and on the Iodine Content of Thyroids of Rats and Monkeys.

Abstract

(i) Studies have been carried out on the absorption, retention, distribution and elimination of fluorine, and on its effect on vitamin C content of different tissues, and on the iodine content of thyroids of  rats and monkeys. (ii) It has been shown that, when 2 mgm. of NaF  dissolved in water is given daily for a period of 20 weeks to rats placed  on normal diet,  (a)  the absorption F is almost complete;  (b)  its retention is 57-6% of that absorbed as against 43.9% of that absorbed in the  rats placed on diet deficient in Ca and  P;  (c)  its distribution and deposition is mainly in the calcified structures, soft tissues containing only a  very small fraction of F retained in the system; (d) among the soft tissues,  the skin together with hair contains the highest amounts of F; brain,  heart, small intestine, kidney, liver and adrenals come next in the order;  (e)  among the calcified structures, humerus contains the highest amount of  F, and vertebrae and epiphyses come next in order  (j)  after the further  administration of F is discontinued, the elimination of F from the sys-  tem, in a period of 12 weeks, is 33.74% of that deposited, and is mainly  through the urinary system  (g)  in terms of percents, the elimination of F is  greater from the soft tissues than from the blood and calcified structures,  and from amongst the calcified structures, it is highest from the incisors,  and then, in descending order, from epiphyses, scapula, ribs and other  bones. (iii) It has been also shown that, as a result of chronic fluorosis,  there is a decrease in the vitamin C content of the tissues, and an increase  in the  I  content of thyroids of both rats and monkeys, and that both  these changes are more marked in monkeys than in rats.