Further studies on a new bioassay of progestational activity (traumatic deciduoma formation in immature rats)

Abstract

Six synthetic steroids were tested subcutaneously in a new bio-assay for short- and long-lasting progestational activity, using traumatic deciduoma production in immature female rats. As reference standard, a daily subcutaneous dose of 0.25 mg progesterone regularly induced a distinct deciduomagenic effect. A single dose of 12.5 mg of progesterone showed a prolonged activity. Medroxyprogesterone acetate showed a distinct deciduomagenic effect at the 0.05 mg daily s.c. dose level; a distinct prolonged effect was induced with a single s.c. injection of 0.5 mg. 16alpha-Aethylprogesterone induced regularly decidual reaction at the 0.1 mg s.c. dose level, it showed prolonged activity at the 0.25 mg dose level. The daily threshold dose for chlormadinone acetate was 0.25 mg; prolonged activity was shown with 2.5 mg. The daily threshold dose for duphaston is between 0.5 mg and 1.0 mg. A single s.c. dose of as much as 20.0 mg of 17alpha- hydroxyprogesterone caproate did not have a deciduomagenic effect.

PIP: 6 synthetic steroids were tested subcutaneously in immature female rats for their ability to produce short- and long-term progestational effects. The bioassay of progestational activity which was used has been described by the authors previously. The DR (decidual reaction) was scored macroscopically and microscopically. The results are illustrated with photographs and tabulated. A daily subcutaneous dose of .25 mg of progesterone, administered as a control to certain of the test groups, regularly produced a marked and prolonged effect. Medroxyprogesterone acetate was found to be 5 times more effective than an equal weight of progesterone. Chlormadinone acetate was about as active and Duphaston was slightly less active than progesterone. Depo-Prolutin was tested only for prolonged progestational activity and was without any deciduomagenic effect at these high dose levels. There were no significant differences in body weight gains of the rats in the various experimental groups. The vaginae of all experimental animals with a positive decidual reaction showed a typical mucification of the epithelial cell layer. The ovaries of all the animals who reacted with a distinct decidual reaction showed histologically no presence of corpora lutea.