Diphenylthiohydantoin の甲状腺腫発生作用について

抄録

Diphenylthiohydantoin (DPTH) is a potent goitrogenic compound and produces a large goiter in rats. Like methimazole, DPTH depresses plasma thyroxine (T₄) and triiodothyronine (T₃) concentrations and elevates plasma TSH concentration. Unlike methimazole, however, DPTH does not suppress thyroidal radioiodine uptake and thyroid hormone synthesis. DPTH does not depress thyroidal radioiodine release nor augment the degradation of thyroid hormone. DPTH depresses an increase of plasma T₃ and T₄ in thyroidectomized, T₄- and T₃-maintained rats by augmenting fecal excretion of hormones. In addition, DPTH depresses peripheral conversion of T₄ to T₃ in vitro.
It is suggested that DPTH is an unique goitrogen which acts on 2 different extrathyroidal sites, viz. fecal loss of thyroid hormone and conversion of T₄ to T₃.