Influence of Thyrotrophin on Growth of Transplantable Thyroid-Gland Tumors of Mice

Abstract

The administration of diets high or low in iodide did not affect the growth rate of independent, mouse, transplantable thyroid-gland tumors of sublines 3C and 4JW. The inclusion of propylthiouracil (PTU) in the diet increased the growth rate at the 6th week and resulted in an alteration in the morphology of the tumors of subline 3C. No significant change could be detected in the histologic features or tumor growth of the 4JW and 6 tumor sublines in the PTU-treated animals. Exogenous thyrotrophin administered for 33 days to mice bearing lines 3C or 4JW resulted in some increased growth of line 3C tumors and some slowing of growth of line 4JW tumors. Similar effects on tumor growth of these lines were obtained in mice subtotally thyroidectomized with radioiodide. In no case was the activity of the iodide pump significantly altered. The thyroid glands of tumor-bearing mice fed PTU did not enlarge as rapidly beyond 3 weeks as did the glands of non-tumor-bearing mice ingesting the goitrogen.