THE OVERT AND MASKED MANIFESTATIONS OF FOLLICULOID HORMONES

¹ From the Department of Anatomy, McGill University, Montreal, Canada

Experiments on immature, spayed, albino rats indicate that in a group of 25 steroids the ability to produce vaginal estrus, stimulation of the mammary gland, enlargement of the uterus and to prevent the appearance of castration cells in the pituitary runs roughly parallel. In other words compounds inactive in one of these respects are also inactive with regard to the other actions mentioned and if the compounds are arranged according to increasing order of activity for one of these actions they automatically are also arranged approximately in increasing order of activity for the other actions. This supports the theory according to which the above effects are merely different manifestations of the same type of action.

Generally speaking all these effects are by far most pronounced in the predominantly folliculoid or "estrogenic" type of hormones and less pronounced in the predominantly testoid, luteoid, corticoid and anesthetic steroids, the activity diminishing in the order mentioned. This is in agreement with their expected activities as predicted by their position in the systematic table of the steroids (8).

All hormonally active compounds, but none of the hormonally inactive steroids tested, were found to possess some degree of folliculoid potency. This supports the view that the folliculoid activity is a common fundamental property of all hormonal steroids.