[Significance of progesterone production in regulating the menstrual cycle]

Premature luteolysis, which can be brought about by injection of a crystalline suspension of estradiol into the ovary carrying the corpus luteum, is cancelled out by a concomitant injection of an appropriate dose of a crystalline progesterone suspension, together with a simultaneous increase in the plasma progesterone level. The authors discuss whether preovulatory production of progesterone has a similar protective influence on the growth and estrogen and androgen production of the vesicular ovarian follicles and the dominant follicle.