Effects of steroids on Tetrahymena.

Phagocytosis of Tetrahymena is inhibited by prednisolone-sodium-succinate and deoxy-corticosterone-glucoside, and stimulated by dexamethasone and prednisolone. Dexamethasone and estradiol enter the cells and are localized first in food vacuoles, and later on in the cytosol. They were never found in the nucleus. The demonstration by biochemical methods of a specific glucocorticoid binding protein failed in all three subcellular fractions examined.