Synergistic effects of DL111-IT combined with mifepristone on termination of early pregnancy in rhesus monkeys

The objectives of this study were to determine the synergistic effects of D L111-IT in combination with mifepristone (RU486) on termination of early pr egnancy in rhesus monkeys. Pregnancy was confirmed by tactile sensation of pregnant uterus via anus with finger and ultrasound examination. Pregnancy termination was obtained with vaginal bleeding and abortion materials inclu ding fetuses and placentae after treatment. With multiple doses of DL111-IT or RU486 given alone between d24 and d50 of gestation, pregnancy arrests w ere obtained in 40% (2/5) of monkeys treated with DL111-IT intramuscularly (im) (25 mg . kg(-1) d(-1) x 3 days), in 20% (1/5) of monkeys treated with 9 mg . kg(-1) d(-1) X 2 days, and 4.5 mg . kg(-1) on day 3 with RU486 intra gastrically (ig). DL111-IT (25 mg . kg(-1) on day 1, im) in combination wit h RU486 (the same treatment as above) resulted in 100% (101/10) termination of pregnancy and uterine bleeding lasted 6.6 +/- 1.3 days. RU486 las above treatment) in combination with misoprostal (Miso, 109 mug . kg(-1) on day 3, ig) showed 71.4% (5/7) termination of pregnancy, and uterine bleeding la sted 12.9 +/- 9.6 days. The synergistic effect of DL111-IT plus RU486 enhan ces termination of early pregnancy and significantly shortens the bleeding time than RU486 plus Mise does in rhesus monkeys. (C) 2000 Elsevier Science Inc. All rights reserved.