Follicular hormone under physiological conditions produced hyperplasia of the muscular wall and proliferation of the mucous membrane of the uterus of rabbits.
The following pathological changes were brought about by prolonged application of large doses of the hormone: (a) hyperaemia of the myometrium and the endometrium, with occasional scanty extravasal haemorrhages; (b) glandular-cystic hyperplasia of the endometrium; (c) infarct-like necrosis of the myometrium; (d) aseptic suppuration in the uterine cavity.
These four processes can sometimes be found simultaneously in the same uterus, but they occur more frequently in sequence. While follicular hormone, applied in physiological doses, has a stimulating effect, prolonged application of large doses destroys the uterus.
The effects described above were only to be observed in the rabbit, not in the rat. This illustrates the fact that hormone reactions may vary in different species.