Biological activities of U-11555A.

a low slope and a subcutaneous med of not less than 5 mg. Its oestrogenic activity intravaginally was not fully investigated, but is not high. It is weakly anti-oestrogenic in similar tests, with an med against oestradiol of about 200 \g=m\gsubcutaneously, perhaps a little lower intravaginally. No interactions were seen as they were with U-11100A\s=d\(Emmens & Martin, 1965). U-11555A has an antifertility action in the mouse when injected on Days 1 to 3 or 4 to 6 of pregnancy, with meds of about 100 \g=m\g(Days 1 to 3) and 300\g=m\g(Days 4 to 6). In rats, U-11555A has a constant subcutan-