The effect of various steroids on mating behavior, fertility, and fecundity of rats.

The effects of WY 3707 ((plus or minus)-13-beta-ethyl-17-alpha-ethynyl- 17-beta-hydroxygon-4-en-3-one) alone and in combination with ethinyl estradiol (EE) norethynodrel estrone estriol testosterone progesterone and norethisterone acetate on mating behavior fertility fecundity and posttreatment recovery of reproductive functions was studied in rats. Subcutaneous injections of WY 3707 at doses up to 1000 mcg and intragastric (ig) administration of up to 300 mcg daily had no effect on mating behavior fertility or fecundity. At 3000 mcg daily ig only 4 of the 8 treated rats vecame pregnant. During treatment with WY 3707 and EE none of the rats became pregnant but the effect seemed dominated by the EE. Norethynodres produced significant infertility during treatment only at the highest doses (1000 mcg ig). Estrone at 3 mcg per day prevented pregnancy in half the animals. At 10 and 30 mcg there were no pregnancies. Mating was delayed after treatment but fertility was restored to all but 2 of the rats who received 30 mcg per day. Litter size was depressed by 30 mcg per day estriol. At 100 mcg this drug produced sterility. Normal fertility and fecundity was restored after treatment. Testosterone and progesterone reduced fertility at high doses but had no residual posttreatment effect. 1000 mcg norethistrone acetate reduced fertility which was restored after treatment.