Studies on the Relation of Diet to Goiter

Publisher Website
Google Scholar
Abstract
A dietary technic suitable for goiter studies employing the rat as the experimental animal has been described. The goiter-producing diet used is low in iodine, having an average content of 15 γ per kilo., and yielding an average daily intake of 0.14 γ per rat. A total of 193 rats were fed the goitrogenic ration for a period of 35 days. The following effects on the thyroid gland were observed: 1.—dark red color; 2.—marked hyperplasia with little or no iodine-containing colloid; 3.—average fresh weight of 53.2 ± .92 mg. per 100 gm. body weight (range, 24.1–126.0 mg.), representing an average enlargement of 4.1–4.2 times the normal gland weight with 2.3–7.9 as the extremes of enlargement; 4.—a low dry matter content—19.0 per cent; 5.—a low concentration of iodine in the gland, i.e., 0.0083 per cent (dry basis) or 0.0016 per cent (fresh basis); and 6.—a low total iodine content per gland of 0.88 γ. The production of goiter on this ration involves essentially a gain in tissue weight of the gland with the moisture content of the gland making a smaller but definite contribution. A total of 24 rats were fed the goitrogenic ration plus added KI to furnish approximately 3.72 γ of iodine per rat daily, yielding the following results on the thyroid gland at the end of 35 days: 1.—normal pale pink color; 2.—normal histological structure with an abundance of colloid; 3.—an average fresh weight of 12.6 ± .19 mg. per 100 gm. of body weight (range, 10.5–16.0 mg.); 4.—a dry matter content of 28.0 per cent; 5.—an iodine concentration of 0.2671 per cent (dry basis) or 0.0745 per cent (fresh basis) and 6.—a total iodine content per gland of 10.28 γ. Comparable results for the thyroid are also given for 39 rats fed on a stock ration containing 47–72 γ of iodine per kilo.