Assessment of a Bioassay of Progestational Activity

Abstract

To test the usefulness of a recently described bioassay of progestational activity (Madjerek, 1972), based on the production of traumatic decidual reaction in immature female rats, a series of agents, known to have some progestational effects in other tests, was investigated for their short-and long-lasting activities.Immature female rats of an inbred commercial Wistar strain were used. Daily administration of a substance was begun 1 day before uterine traumatization and continued once daily for 5 days. To test prolonged activity, the substance was given in one single injection 1 day before traumatization. On the 5th day after traumatization, the rats were killed and the uteri removed.The decidual reaction (DR) was scored macro-and microscopically according to an arbitrary scale (1-4) and expressed as the deciduoma index (DI), arrived at by dividing the sum of all individual values in one experimental group by the number of animals in that group. The DI values from 2 to 4 are taken as characteristic of marked progestational activity in this test.The substances tested and the results are summarized in Table 1. As reference standard, a daily subcutaneous dose of 0-25 mg progesterone regularly induced a distinct decidual reaction, while a single subcutaneous dose of 12-5 mg progesterone showed a marked prolonged activity and the lower dose levels (7-5 mg and less) were ineffective. Table 1. The activities of a series of progestational steroids in the production of traumatic decidual reaction (DR) in immature female rats Substance Progesterone 0-25 mg daily 1x12-5 mg 1 7-5 mg

Maintenance of Decidual Cell Reaction by Androgens in the Mouse1

“…This model of hormonal regulation of DCR has been used extensively to study the endocrine requirement for embryo implantation, a critical process in the establishment of pregnancy. Sensitization of the uterus for DCR and maintenance of DCR have also been used as bioassays for synthetic progestins [10,11].…”