Effects of (-)-5-Vinyl-2-Oxazolidinethione on the Radioiodine Metabolism in Growing Chicks

IT HAS been established that (-)-5-vinyl-2-oxazolidinethione (goitrin), a goitrogen in rapeseed, enlarges the thyroid gland and affects the iodine metabolism. Astwood et al. (1949) reported that the goitrogenic activity of goitrin was 1.33 times that of propylthiouracil (PTU) on man and that it was 1/55 that of PTU on rats. Recently Faiman et al. (1967) reported that goitrin was found to be 1/150 as potent as PTU after oral administration to rats. However, Iino (1961) reported that the goitrogenic activity of goitrin on rats was equal to PTU in in vitro experiments. In our previous report (Matsumoto et al., 1968), thyroic enlargement, increased thyroid 131 I uptake, slow release of 131 I from the thyroid gland and decreased thyroid hormone in the blood was observed in growing chicks fed 0.05% goitrin for 14 days. Furthermore, it was stated that goitrin was different from other goitrogens, such as 1-methyl-2-mercaptoimidazole and 6-methylthiouracil (MTU), in…