Thio-Ureas as Goitrogenic Substances

Abstract

AN attempt to isolate the goitrogenic substance present in rape seed^1,2 suggested the possibility of its being a derivative of this urea. Allyl thio-urea was therefore tested. Doses of 20 mgm. were given to rats daily by stomach tube for a period of eight weeks, after which the thyroids were examined. They had an average weight of 43 mgm., this being three to four times the normal weight. Histologically, the glands show extreme hypertrophy and hyperplasia, and almost complete loss of colloid. The administration of 50 mgm. daily by stomach tube, for ten days, produced identical histological changes in the thyroid, although the weight of the gland is not so great—average of 30 mgm. per 60 gm. body weight. This dose had no toxic effect. Preliminary experiments with 200 mgm. of thio-urea daily for ten days have produced similar results. The changes in both thyroid and pituitary are similar to those produced by feeding rats a diet containing rape seed^2,3.