Action of Pregnancy Urine Extract (Follutein) on the External Genitalia of Female Guinea Pigs. ∗

Abstract

Injections of Follutein† into sexually immature female guinea pigs produce an enlargement of the clitoris. Animals treated over a long period show a considerable enlargement. The clitoris takes the form of a typical penis which protrudes when the surrounding tissues are subjected to pressure. The prepuce, the corpus cavernosum, and the glans are well differentiated. The size of the enlarged clitoris is considerably smaller than the size of a male penis, in animals of corresponding age. Adult female guinea pigs treated with Follutein respond likewise, although the growth of the clitoris is less pronounced than in the young females.

Experiments were made on a group of 48 animals. After the administration of 3–5 cc. of Follutein over a period of about 10 days, changes can be observed in the clitoris. These become very pronounced after a more prolonged administration over 4–6 weeks.

The results do not imply necessarily a specific action. The histological examination of an experimentally enlarged penis-like clitoris reveals a general enlargement of the organ. No definite specific effect is noticeable in any of its tissues.

A marked increase in circulation and pronounced swelling in the external genital region appear after treatment. Vascular changes as a result of injections of pregnancy urine have been noticed previously by Papanicolaou. 1 He advanced the hypothesis that the luteinizing effect on the ovaries, as well as the stimulating action upon other glands, might be interpreted as being primarily due to vascular changes.

Preliminary work on ovariectomized animals shows that the growth potentiality of the clitoris almost disappears after complete removal of the ovaries. There is, however, an indication of a circulatory stimulation. This suggests that at least 2 separate factors are involved. One factor induces congestion and swelling and acts primarily on the clitoris itself; the other factor induces growth and acts secondarily through the stimulation of the ovaries.