The present study describes the effects of 11 steroid hormones and 3 non-steroidal antiestrogens on the 3H-thymidine uptake by human endometrial and endosalpinx cells in long-term cultures. The compounds were added in various concentrations ranging from 10(-9) to 10(-4) M. Progesterone and 19-nortestosterone caused a dose-dependent reduction of the 3H-thymidine incorporation resulting in a 94-98% inhibition at a concentration of 10(-4) M, gestonoroncaproate and d,1-norgestrel were less effective causing a 49% and 40% decrease. Antiproliferative effects were also noted after the addition of androgens (testosterone, 5 alpha-dihydrotestosterone, 5 beta-dihydrotestosterone and danazol). The inhibitory effect of testosterone was equivalent to progesterone at concentrations of 10(-4) M. The addition of estrogens (estrone, estradiol-17 beta and estriol) and antiestrogens (tamoxifen, N-desmethyl- and 4-OH-tamoxifen) produced a dual response in monolayer cultures as low concentrations (10(-9)-10(-6) M) were associated with a slightly increased 3H-thymidine incorporation while pharmacological concentrations (10(-5)-10(-4) M) were followed by a significant decrease. Cells originating from the endosalpinx did not respond to either estradiol-17 beta or progesterone. These results suggest that in contrast to endometrium, the proliferation of endosalpinx cells is independent of sex steroids.