THE ACTION OF TESTOSTERONE PROPIONATE ON EXPERIMENTAL MENSTRUATION IN THE MONKEY1

Abstract

The minimal effective dose of testosterone propionate for postponing menstruation in monkeys after 50 [gamma] of estrogen daily for 10 days was approx. 1 mg. The interval between cessation of an effective inhibiting dose of testosterone and the onset of bleeding was similar to that following withdrawal of estrogen; both were longer than that following withdrawal of progesterone as stressed by Engle. In the monkey receiving continuous estrogenic treatment at the same dose level, it was shown previously that after supplementary adm. of progesterone, bleeding occurred. In a similar expt. the use of testosterone instead of progesterone was not followed by bleeding. In addition to the different histologic response of the endo-metrium as shown by Engle, there was a different physiologic action of testosterone and progesterone.