The Effect of Altered Thyroid State on Prolactin Binding to Liver and 7,12-Dimethylbenz(a)anthracene-Induced Mammary Tumors in Rats 1

Abstract

Summary

The effects of propylthiouracil (PTU) and pharmacological doses of thyroxine (T₄) on growth and prolactin (PRL)-binding activity of DMBA-induced mammary tumors were studied. The hypo- or hyperthyroidism induced by these respective treatments did not affect the growth rate of established tumors, PRL binding activity in these tumors or plasma PRL in the tumor-bearing rats. In contrast, both PTU and T₄ treatments caused a large reduction of PRL binding activity in the liver.