CHANGES IN THE NUMBER OF MOUSE THYROTROPES FOLLOWING RADIOTHYROIDECTOMY

Abstract

ABSTRACT Mouse thyrotropes were identified as alcian blue positive cells. Their frequency was found to drop from 0.87% in normal animals to 0.11% in animals radiothyroidectomized since 30 days. This decrease is only apparent since a pulse feeding of thyroxine to radiothyroidectomized mice caused a regranulation of the TSH-depleted cells and revealed as many as 2.93% alcian blue positive cells. Since no mitoses were found to account for the increased number of thyrotropes, it is likely that radiothyroidectomy »mobilized« other existing pituitary cells, possibly chromophobes.