THE ACTION OF SMALL QUANTITIES OF PROGESTERONE

Abstract

OF THE MANY effects that have in the past been attributed to the corpusluteum hormone (progesterone) there are only two that are used as a basis for rational biological determination of its strength: a), that of rendering the endometrium of spayed rats, mice and guinea pigs sensitive to the formation of deciduomata (I,2,3); and, b), the production of the pregravid phase (the decidual or secretory phase) in the endometrium of rabbits. The latter test, which was first described by Corner and Allen (4), later modified by Clauberg (5), and which has since been described many times in the literature (6,7,8) is the most accurate and the one most used. It is usually carried out-as, for instance at the biological laboratory at L0vens kemiske Fabrik, Copenhagen-by Clauberg2s method. The hormone is injected into immature rabbits that have previously been treated with estrin and the endometrium is subsequently examined histologically. Determination of potency by this method shows that about 0.75 mg.