contraceptives--postcoital and anordrin

The in vitro effect of anordrin and anordiol on the development of mouse two-cell embryos was studied.. Female mice were primed with gonadotropins for superovulation and caged with male mice. Preimplantation embryos, at the two-cell stage, were recovered from the oviducts at 40 hr post-hCG. In the first experiment, two-cell embryos were exposed to culture medium containing different concentrations of anordrin for 3, 12, 24, and 80 hr and then grown in the anordrin-free culture medium and assessed for the formation of total and hatching blastocysts at 80 hr. In the second experiment, two-cell embryos were grown in culture medium containing different concentrations of anordiol and assessed for the formation of total and hatching blastocysts at 80 hr in vitro.. Exposure of two-cell embryos to anordrin concentrations of 2.5-7.5 micrograms/ml for 12 hr, 2.5-5.0 micrograms/ml for 24 hr, and 2.5 micrograms/ml for 80 hr caused significant inhibition of the formation of total blastocysts and to 2.5-7.5 micrograms/ml for 12 hr, 1.0-2.5 micrograms/ml for 24 hr, and 1.0 micrograms/ml for 80 hr caused significant inhibition of the formation of hatching blastocysts, in a exposure time-dependent and dose-dependent manner. Exposure of two-cell embryos to anordiol concentrations of 15-25 micrograms/ml for 80 hr caused significant inhibition of the formation of total blastocysts and to 15-20 micrograms/ml for 80 hr caused significant inhibition of the formation of hatching blastocysts in a dose-dependent manner.. Anordrin and its metabolite anordiol inhibit the development of two-cell embryos in vitro.

Topics: Animals; Contraceptives, Postcoital; Embryo, Mammalian; Embryonic and Fetal Development; Embryonic Development; Female; Male; Mice; Norandrostanes; Organ Culture Techniques; Pregnancy; Time Factors

To develop a better postcoital contraceptive, the following antiestrogens were tested for their anti-implantation activity in the rat: anordrin, anordiol, tamoxifen, ICI 182,780, and RU 39411. The compounds were administered orally or subcutaneously (s.c.) to female rats on days 1, 2, and 3 of pregnancy. All the antiestrogens tested were 100% effective in preventing blastocyst implantation. The lowest effective doses when administered orally were 10, 1.25, 0.062, 6.0 (partially effective), and 0.01 mg/kg/day, respectively. The estimated median effective doses (ED50) were 5.60, 0.40, 0.035, 5.40, and 0.0074 mg/kg/day, respectively. When administered s.c., the minimum effective doses in preventing blastocyst implantation in all animals were 2.0, 0.1, 0.1, 0.1, and 0.01 mg/kg/day, respectively. Anordrin, anordiol, and ICI 182,780 were more potent when administered s.c.; whereas tamoxifen and RU 39411 were effective at similar doses when administered parenterally or orally. RU 39411 was the most potent among the antiestrogens tested and should be evaluated as a potential postcoital contraceptive. The administration of mifepristone, an antiprogestin, at a dose of 8 mg/kg/day blocked blastocyst implantation in all treated animals; whereas at a dose of 4 mg/kg/day or lower, the drug was ineffective. These findings confirm that estradiol and progesterone are essential for blastocyst implantation in the rat. The capacity of mifepristone to potentiate the anti-implantation activity of the antiestrogens was also determined. The combination of a non-effective dose of each of the antiestrogens (anordrin, anordiol, and tamoxifen), and RU 39411, with mifepristone at a non-effective dose, prevented pregnancy, demonstration that an antiprogestin and antiestrogen act synergistically in blocking blastocyst implantation in the rat. The antiestrogen compounds whose anti-implantation activities were potentiated by mifepristone were found to possess significant estrogenic activity, when assayed by measuring the increase in the uterine weights of ovariectomized rats. The only exception was ICI 182,780, which showed no estrogenic activity in the uterine weight bioassay and did not act synergistically with mifepristone in blocking blastocyst implantation. Estradiol was effective in preventing pregnancy at a dose of 1 microgram/kg/day. The combination of non-effective doses of estradiol and mifepristone did not prevent pregnancy. The findings that mifepristone potentiates the anti-. In New York, female and male rats copulated on the afternoon of proestrus as part of a study aiming to determine whether antiestrogens alone or in combination with mifepristone (RU-486) will block blastocyst implantation in the rat. This study is part of research efforts to develop a better postcoital contraceptive. The antiestrogens included RU39411; ICI 182,780; anordrin; anordiol; tamoxifen; and estradiol. The laboratory researchers treated the rats orally or subcutaneously on days 1, 2, and 3 of pregnancy. They killed them on day 8-9 to examine the uteri for the presence or absence of implanted embryos. All the antiestrogens effectively prevented blastocyte implantation. Using the measurement mg/kg/day, the lowest effective oral dose was 10 for anordrin; 1.25 for anordiol; 0.062 for tamoxifen; 6 (80% effective) for ICI 182,780; and 0.01 for RU 39411. These antiestrogens' estimated median effective doses were 5.6, 0.4, 0.035, 5.4, and 0.0074 mg/kg/day, respectively. In all animals, the minimum effective doses administered subcutaneously were 2, 0.1, 0.1, 0.1, and 0.01 mg/kg/day, respectively. Anordrin, anordiol, and ICI 182,780 were more effective during subcutaneous administration while tamoxifen and RU 39411 were as effective at similar doses during parenteral or oral administration. The most potent antiestrogen was RU 39411. This antiestrogen should be evaluated as a potential postcoital contraceptive. An 8 mg/kg/day dose of RU-486 blocked blastocyst implantation in all rats. The 4 mg/kg/day dose was completely ineffective. RU-486 augmented the activity of anordrin, anordiol, tamoxifen, and RU39411 synergistically, resulting in prevention of pregnancy at non-effective doses of RU-486 and the antiestrogens. These same antiestrogens also exhibited significant estrogenic activity as determined by an increase in uterine weights of ovariectomized rats. Estradiol prevented pregnancy at a dose of 1 mcg/kg/day. RU-486 did not potentiate estradiol. These findings suggest that the synergistic effect of anordrin, anordiol, tamoxifen, and RU39411 may be unique to these antiestrogens.

Topics: Administration, Oral; Animals; Contraceptives, Postcoital; Embryo Implantation; Estradiol; Estrogen Antagonists; Female; Fulvestrant; Injections, Subcutaneous; Male; Mifepristone; Norandrostanes; Pregnancy; Rats; Rats, Sprague-Dawley; Tamoxifen; Uterus

The molecular structures and absolute configurations of alpha- and beta-anordrins are reported. Animal experiments showed that pure alpha-epimer possessed high anti-implantation and anti-early pregnancy effects, but the pure beta-epimer exhibited very low effects at the same dose. MNDO program was applied for the optimization of the configurations of epimers to establish the isolated molecular configurations and calculate the quantum chemical indexes. The results showed that the configurations and the differences of action field in three-dimensions of alpha- and beta-epimer are probably the factors that the alpha-epimer exhibited biological activity.

Topics: Animals; Contraceptives, Postcoital; Embryo Implantation; Female; Mice; Molecular Conformation; Norandrostanes

In order to determine the pharmacokinetics of anordrin a dose of 0.2 mg/kg of [3-14 C]anordrin was administered i.v. to 5 cynomolgus monkeys; the same monkeys received the same dose i.m. at a later date. An additional 3 monkeys received 1.0 mg/kg of [3-14C]anordrin i.m. After administration of the compound, the dipropionate esters of anordrin were rapidly hydrolyzed to the dihydroxy parent compound, anordiol. After i.v. administration, anordrin had a mean residence time (MRT) of 5.0 +/- 1.3 (SE) min. [14C]Anordiol formed from [14C]anordrin had an MRT of 139 +/- 27 (SE) min. The metabolic clearance rates (MCR) of anordrin and anordiol were 55 and 34 mL/min.kg, respectively. The apparent volume of distribution at steady state (Vss) for anordrin was 276 mL/kg, 7.5% of body weight of the animals; anordrol had a much larger Vss of 4460 mL/kg. The MRT of anordiol after i.m. administration of 1.0 mg/kg of [14C]anordrin was 26.3 days. An average of 44% of the dose appeared in urine regardless of the route of administration or dose. The MRT values of total radioactivity were the same when calculated from serum or urine after an i.v. dose, but after i.m. administration, values from urine were approximately 60% of that calculated from serum, indicating that products appearing in urine had a shorter MRT than products appearing primarily in feces. A separate group of monkeys was given anordrin i.m. in doses ranging from 0.1 to 0.4 mg/kg on the first day of menses. The regression of length of menstrual cycle on dose was significant (P = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Contraceptives, Postcoital; Female; Half-Life; Injections, Intramuscular; Injections, Intravenous; Linear Models; Macaca fascicularis; Menstrual Cycle; Molecular Structure; Norandrostanes

The effectiveness of oral RU 486 and anordrin given alone and in combination for terminating early pregnancy was tested in the rat, rabbit, and hamster. In the rat and rabbit, the combination of RU 486 and anordrin is more effective in terminating pregnancy than either of the two compounds used alone. A non-effective dose of RU 486 combined with a non-effective or a sub-effective dose of anordrin, or a low effective dose of RU 486 in combination with a non-effective dose of anordrin, exerted additive or synergistic effects resulting in resorption of embryos and termination of pregnancy in rats and rabbits. The serum progesterone as well as estradiol concentrations were significantly suppressed by these combinations when pregnancy was terminated. In the hamster, however, RU 486 was not effective in interrupting early pregnancy, even at a 4-fold higher dose than was effective in the rat, due to the fact that RU 486 does not bind to the progestin receptor in this species. Unexpectedly, there were also no effects of anordrin on pregnancy termination in the hamster even at high doses. It is concluded that in rat and rabbit, the synergistic action between RU 486 and anordrin not only greatly enhances efficacy in terminating pregnancy but also reduces substantially the doses required to produce this effect.

Topics: Abortifacient Agents, Steroidal; Abortion, Induced; Animals; Contraceptives, Postcoital; Cricetinae; Drug Interactions; Estradiol; Female; Mifepristone; Norandrostanes; Pregnancy; Progesterone; Rabbits; Rats; Species Specificity

The effect of various doses of anordrin and RU 486, alone or combined, on serum progesterone (P) levels, fetal resorption, and recovery of ovulation was studied in mice. Each drug was given as a single sc injection on day 7 of pregnancy and autopsy was performed on days 8, 9, or 11. Serum P was normal at 24 h but fell significantly 48 h after treatment with anordrin (0.05 mg). Doses of 0.05 or 0.2 mg anordrin were effective in interrupting pregnancy in 30% and 70% of pregnant mice, respectively. RU 486, 0.01 mg per mouse, induced a pronounced decrease of P levels 24 h after treatment and interrupted pregnancy in 50% of pregnant mice. The combined treatment with submaximal doses of anordrin plus RU 486 did not further decrease P levels, but increased the proportion of mice with fetal resorptions to 90%. The combination of small doses of anordrin with RU 486 had an additive effect on pregnancy termination. The additive effect required a dose of RU 486 above the threshold level. Direct observation of aborted fetuses indicated that the resorptive process occurred earlier with RU 486 than with anordrin. Recovery of ovulation was associated with pregnancy termination in a high proportion of mice treated with either drug or their combination.

Topics: Abortion, Induced; Animals; Contraceptives, Postcoital; Dose-Response Relationship, Drug; Drug Synergism; Female; Fetal Resorption; Injections, Subcutaneous; Mice; Mifepristone; Norandrostanes; Ovulation; Pregnancy; Pregnancy, Animal; Progesterone

Because RU 486 synergizes with anordrin and its dihydroxylated metabolite to terminate established pregnancy in the rat and rabbit, the interactions of these agents were studied at two days postcoitally in the rat. RU 486 at a dose of 4 mg/kg did not prevent pregnancy when the animals were killed 12 days post insemination. A 2.5 mg/kg dose of anordrin prevented pregnancy in 14% of animals. By contrast, none of the animals became pregnant when treated with 2.5 mg/kg of anordiol. A non-effective dose of RU 486 (2 or 4 mg/kg) combined with a non-effective dose of anordrin (1.25 or 2.5 mg/kg) prevented pregnancy in all animals treated; there was no evidence of implantation sites or embryos when the animals were killed on day 12 post insemination. The same synergistic effect was observed when a small dose of RU 486 (e.g., 1 mg/kg) was combined with 0.6 mg/kg anordiol. To investigate the mechanism of pregnancy prevention, animals were treated two days postcoitally with 4 mg/kg of RU 486 plus 2.5 mg/kg of anordrin or 2 mg/kg of RU 486 plus 0.6 mg/kg of anordiol and were killed short intervals after treatment. These drugs had no effect by 6 h, but the numbers of embryos in oviducts were significantly reduced 12 h after treatment. By 24 h following treatment, no embryos were recovered from either the oviduct or the uterus. Progesterone and estradiol levels in serum collected 24 h after treatment were not significantly different from those of controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Contraceptives, Oral, Synthetic; Contraceptives, Postcoital; Drug Combinations; Drug Synergism; Embryo Implantation; Estradiol; Female; Male; Mifepristone; Norandrostanes; Ovum; Progesterone; Rats; Rats, Sprague-Dawley; Time Factors

We describe the chemical synthesis of the 2 beta-propionate-17 beta- hemisuccinate and 2 beta-hemisuccinate-17 beta-propionate diesters of anordiol (2 alpha,17 alpha-diethynyl-A-nor-5 alpha-androstane-2 beta,17 beta-diol) and the method for coupling them to bovine serum albumin and Affi-gel 102, in order to prepare antibodies for radioimmunoassay of anordrin. In addition, we describe the chemical synthesis of the following derivatives: 2 beta-ol-17 beta-propionate, 2 beta-propionate-17 beta-ol, 2 beta-hemisuccinate-17 beta-ol, and 2 beta-ol-17 beta-hemisuccinate.

Topics: Antibodies; Contraceptives, Postcoital; Esterification; Esters; Magnetic Resonance Spectroscopy; Mass Spectrometry; Norandrostanes; Radioimmunoassay

The delay in appearance of vaginal cornification associated with administration of anordiol (de-esterified anordrin) in the post-ovulatory period was confirmed. Ovarian tissue incubated in vitro for 2 h on the day which, in normal cycles, would be the day of proestrus produced negligible amounts of estradiol even in the presence of androstenedione and human menopausal gonadotropin, despite the appearance of apparently mature follicles in the ovaries. Ovaries of untreated rats produced significant amounts of estradiol when androstenedione was present. Continued incubation for 3 days resulted in significant estradiol production by ovaries of anordiol-pretreated rats in the presence of androstenedione, but less than that of ovaries of control rats. Granulosa cells of immature rats pretreated with diethylstilbestrol (DES) were unaffected by pretreatment with anordrin, whether anordrin was given before or after DES treatment. Taken together, the results indicate that anordiol inhibits development of the capacity for estrogen secretion in maturing follicles without affecting structural development, but that follicles that grow under the influence of high concentrations of estrogen (DES) are unaffected by the presence of anordrin (which is rapidly converted to anordiol in vivo). The latter result suggests that DES treatment bypasses the anordiol-sensitive step in follicular maturation.

Topics: Analysis of Variance; Androstenedione; Animals; Cells, Cultured; Contraceptives, Postcoital; Diethylstilbestrol; Drug Administration Schedule; Estrogens; Estrus; Female; In Vitro Techniques; Injections, Subcutaneous; Luteolytic Agents; Menotropins; Norandrostanes; Ovary; Radioimmunoassay; Rats; Rats, Inbred Strains

RU-486 and anordrin suspended or dissolved in tea seed oil, alone or in combination, were given orally to rats on d 6-8 or d 11-13 of pregnancy, respectively. Complete interruption of early pregnancy was obtained after RU-486 at 8 mg/kg alone or 2.5 mg/kg combined with anordrin 2 mg/kg when given on d 6-8 of pregnancy. A complete mid-trimester abortion was obtained after RU-486 10 mg/kg alone or 4 mg/kg combined with anordrin 3 mg/kg when given on d 11-13 of pregnancy. Results obtained from the endometrial transformation test, the uteri cytoplasmic progesterone receptor estimation in immature rabbits, the deciduoma-inhibited test in pseudopregnant rats and the serum progesterone level in pregnant rats showed that RU-486 in combination with anordrin did not possess progestational, but rather marked antiprogestational activities. Since anordrin is relatively easy to obtain in China, RU-486 combined with anordrin may be ready to be used clinically as an effective oral antifertility agent.

Topics: Abortifacient Agents, Steroidal; Abortion, Induced; Animals; Contraceptives, Postcoital; Decidua; Drug Therapy, Combination; Female; Mifepristone; Norandrostanes; Pregnancy; Progesterone; Pseudopregnancy; Rabbits; Rats; Rats, Inbred Strains

Twenty four mice were divided randomly into experimental and control groups. There were 10 animals in the control group. In experimental group, anordrin (3 mg/kg) was injected into the peritoneal cavity to terminate early pregnancy. The control group was treated with normal saline. Pathological changes in the decidual cells, blastocysts (including giant cells), corpora lutea and embryo were observed. It was found that the animals in the control group were developing normally. In all the experimental groups decidual cells and blastocysts showed degeneration and necrosis. The granulosa lutein cells also showed degeneration. The dead embryo was embedded in the necrotic decidual cells and blastocysts. The mechanism concerned may involve a combination of various factors. The degeneration of granulosa lutein cells may be the most important of the factors.

Topics: Animals; Blastocyst; Contraceptives, Postcoital; Corpus Luteum; Decidua; Embryo, Mammalian; Female; Injections, Intraperitoneal; Luteal Cells; Mice; Norandrostanes; Pregnancy

The coprecipitate of anordrin (AD)-PVP was prepared by solvent method. The DSC (differential scanning calorimetry) revealed that AD did not have crystalline structure in coprecipitates of 1:7-1:9. X-ray diffraction spectrum of 1:8 coprecipitate (COPPT) showed no crystalline structure of AD. The dissolution rate of AD was about 38 times higher for 1:8 COPPT than pure AD. Activation energies determined by DTG (derivative thermogravimetry) were 182.8 and 133.4 kJ/mol, respectively, showing that the 1:8 COPPT is much more stable than pure AD in thermal degradation. The experimental results showed that anti-implantation effect of the 1:8 COPPT was much better than that of AD tablets: the number of implantation sites of mice administrated 1:8 COPPT (5 mg/kg) was 0.2 (P less than 0.01) and that of mice administrated AD tablets (10.6 mg/kg) was 0.9 (P less than 0.05); effective dose of 1:8 COPPT was less than half of that of AD tablets.

Topics: Animals; Calorimetry, Differential Scanning; Chemical Precipitation; Contraceptives, Postcoital; Drug Compounding; Embryo Implantation; Female; Mice; Norandrostanes; Povidone

Topics: Animals; Contraceptives, Postcoital; Corpus Luteum; Embryo Implantation; Embryonic and Fetal Development; Female; Luteolytic Agents; Norandrostanes; Pregnancy; Progesterone; Rabbits

Anordrin, administered in a single s.c. dose of 62.5 micrograms in sesame oil, stimulated sustained uterine growth (wet weight) when measured at 24 and 72 hr, but total soluble protein and total DNA per uterus was not increased. By comparison, 3 micrograms of estradiol-17 beta under the same conditions significantly increased all three parameters of uterine growth. Both of the above steroid treatments significantly increased nuclear estrogen receptor content of the uterus, but only the estradiol-17 beta treatment resulted in significantly elevated cytosol receptor content per uterus. Anordrin binds to the 8S estrogen receptor with an affinity of about 2 x 10(5) M-1 as determined by competition with [3H]estradiol-17 beta. The abortifacient activity of Anordrin when given orally (8 mg/kg b.w.) to mice on the 7th day of pregnancy was almost completely blocked by simultaneous oral administration of estradiol-17 beta (0.8 mg/kg b.w.). It is concluded that the actions of Anordrin on the uterus can be attributed to its antiestrogenic activities.

Topics: Abortifacient Agents; Abortifacient Agents, Steroidal; Animals; Contraceptives, Oral; Contraceptives, Oral, Synthetic; Contraceptives, Postcoital; Estradiol; Female; Mice; Norandrostanes; Receptors, Estrogen

Two A-nor steroids, Anordrin and H241, showed a marked antifertility effect when given orally to hamsters at 10 mg/kg/day for three or four days after mating. Further study indicated that the antifertility effect was due to a disturbance of egg transport, retarded development and degeneration of fertilized eggs.

Topics: Animals; Cleavage Stage, Ovum; Contraceptives, Postcoital; Cricetinae; Embryo Implantation; Fallopian Tubes; Female; Norandrostanes; Ovulation; Ovum; Ovum Transport; Rabbits; Uterus