Cytologic alterations in the anterior pituitary gland following thyroidectomy: an electron microscope study.

INTRODUCTION IN THE course of a detailed study of the cytology of the anterior pituitary gland as revealed by electron microscopy, a series of rats were subjected to thyroidectomy. It soon became evident that alterations of a distinctive character occurred in certain of the basophils which served to distinguish them from the basophils stimulated by gonadectomy. The characteristic fine structural alterations which occur following gonadectomy have been described in detail (Farquhar and Rinehart, 1954). Examination of the early response to thyroidectomy has enabled us to recognize the unstimulated thyrotrophic cell in the normal animal. It is the purpose of this report to indicate the fine structural organization of this cell and its response to thyroidectomy as well as to contrast it with the gonadotroph of the normal animal and the castrate. The studies of Purves and Griesbach (1951a, b) and Halmi (1950 and 1952) have served importantly as guides in our recognition of the thyrotroph.