A Crystalline Substance of the Hypophysis Which Promotes Follicular Growth

While working with an acid alcohol extract of the anterior lobe of the pituitary body, according to the earlier method of Hisaw, Fevold, and Meyer, 1 it was found possible to produce 2 very different ovarian reactions depending upon the dosage used. When a small amount of the extract was injected into adult rats, follicular growth increased and the rats remained in a condition of oestrum much longer than normally. On the other hand, if a larger amount of the same extract was injected the follicles in the ovary became atretic with the formation of corpora lutea without ovulation, the animal remaining in a state of dioestrum.

Attempts were then made to separate the extract into fractions which would give one of the above mentioned physiological effects without the other. This was done by following the unpublished technique used by Hisaw in making an extract of corpus luteum hormone. An acid alcohol extraction of desiccated anterior lobe was, during the process of purification, separated into one fraction which was soluble in absolute alcohol and one which was not. From the latter a crystalline product was secured which induces precocious sexual maturity. Such crystals when injected in aqueous solution into 18 day old mice, in amount equivalent to 1/2 gm. of fresh material per day, invariably caused the vagina to open in from 2 to 3 days. Normally the vagina remains closed until about the thirty-fifth day (30th to 49th day). The ovaries of the treated mice showed numerous and large mature follicles and in those animals which were not killed ovulation always occurred.