Effect of testosterone on estrogen-induced accumulation of intrauterine fluid in rats.

The effect of various doses of testosterone propionate (Tp) (twice 0.01 to 10 mg i.m. in two days) on the accumulation of intrauterine fluid produced by various doses of estradiol benzoate (Eb) (twice 0.2 to 200 microgram i.m. in two days) was studied in ovariectomized adult rats. A small dose of Tp (0.01 mg) augmented the effect of a moderate dose of Eb (2 microgram). Higher doses of Tp inhibited the effect of Eb. The inhibition of the smallest Eb dose (0.2 microgram) began with a lower dose of Tp (0.1 mg) than the inhibition of other Eb doses (for 2 microgram and more EB 1 mg was necessary). There is a similarity of the action of Tp to that of progesterone.