THE EFFECT OF THYROXIN INJECTIONS ON THE THYROTROPHIN CONTENT OF THE ANTERIOR PITUITARY OF THE MALE ALBINO MOUSE¹

THE PROBLEM OF PLACENTAL PERMEABILITY FOR THYROTROPHIN, PROPYLTHIOURACIL AND THYROXINE IN THE GUINEA PIG1

“…The thyroid epithelium was not flattened nor was there enlargement of the follicles as we might have expected from work of Courrier (1928) and Adams and Jensen (1944), but the thyroids were significantly smaller than those of control newborn (Table 1). The greater the dose of thyroxine, the smaller were the thyroids.…”

“…The administration of thyroid hormone to an intact adult animal causes flattening of the thyroid epithelium and enlargement of the follicles (Courrier, 1928;Adams and Jensen, 1944). If thyroxine passes the placental barrier, the administration of this substance to pregnant guinea pigs might cause similar changes in the fetal thyroids.…”