anordrin and anordiol

1. Anordrin (2α, 17α-diethynyl-A-nor-5α-androstane-2β, 17β-diol diproprionate) is post-coital contraceptive drug that is on the market in China for more than 30 years. This study aims to elucidate enzymes involved in anordrin hydrolysis, and to evaluate the significant role of carboxylesterases in anordrin hydrolysis in humans. 2. Human liver and intestinal microsomes, recombinant human carboxylesterase were selected as enzyme sources. In human liver microsomes, intrinsic clearance was 684 ± 83 μL/min/mg protein, which was considerably higher than the value of intestine microsomes (94.6 ± 13.3 μL/min/mg protein). Carboxylesterase (CES) 1 has more contribution than CES2 in human liver. 3. Inhibition studies were performed using representative esterase inhibitors to confirm esterase isoforms involved in anordrin hydrolysis. Simvastatin strongly inhibited hydrolytic process of anordrin in liver and intestine microsomes, with IC

Topics: Carboxylesterase; Humans; Hydrolysis; Ions; Kinetics; Microsomes, Liver; Norandrostanes; Simvastatin

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

In view of the unexpected ability of anordrin to synergize with RU 486 in terminating pregnancy, it was pertinent to examine the actions of the dihydroxylated metabolite of anordrin, anordiol, alone and in combination with RU 486. Does of RU 486 (1 mg/kg/day) and anordiol (0.6 mg/kg/day) that were ineffective when given alone terminated pregnancy with complete resorption of embryos when administered together. A smaller dose of anordiol than anordrin is required to achieve this synergistic effect with RU 486. This anordrin metabolite increased uterine weight in the ovariectomized rat similar to estradiol. The estrogenicity of anordiol in the uterine weight assay was about 1/120 of that of estradiol. Anordiol does not exert antiestrogenic activity in the uterine weight assay when administered at doses that terminate pregnancy. Administration of anordiol at doses that do not terminate pregnancy resulted in a significant suppression of serum progesterone concentrations during the period of medication; these observations suggest that anordiol has an inhibitory effect on progesterone biosynthesis. When the same dose of anordiol was given concomitantly with sufficient RU 486 (e.g., 1 mg/kg/day) to terminate pregnancy, the progesterone levels were reduced to low levels throughout the experiment. These observations support the postulate that the actions of anordrin are mediated by its metabolite, anordiol. The administration of anordiol plus RU 486 results in a more dramatic change in the functional progesterone:estradiol ratio than when either agent is administered alone.

Topics: Abortifacient Agents, Steroidal; Abortion, Induced; Animals; Drug Interactions; Drug Synergism; Estradiol; Female; Mifepristone; Norandrostanes; Organ Size; Pregnancy; Progesterone; Rats; Rats, Sprague-Dawley; Uterus

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

Cell suspensions were prepared from human corpora lutea obtained during the mid-luteal phase. Progesterone production was assessed after short-term incubation of luteal cell suspensions. Luteal cells were very sensitive to hCG, the concentration required for 50% maximum response being 0.01 i.u./ml, and the response was 5 times higher than the basal production. Oestradiol (1-100 microM) induced a significant dose-related decrease in both basal and hCG-stimulated progesterone production. The A-nor steroidal compounds anordrin and AF-45 reduced hCG-stimulated progesterone production only at the high concentration of 100 microM. The ED50 values were approximately 3 microM, 75 microM and 100 microM for oestradiol, AF-45 and anordrin respectively. Anordrin showed no significant effects on basal progesterone production. In addition, oestradiol markedly inhibited the activity of 3 beta-hydroxysteroid dehydrogenase in luteal cells, expressed by the conversion of pregnenolone to progesterone, but the inhibitory effects of anordrin and AF-45 were negligible or relatively low. The effects of anordrin and AF-45 were different from those of oestradiol on progesterone production by human luteal cells in vitro, indicating that neither substance is likely to be a useful luteolytic agent in women.

Topics: Cells, Cultured; Corpus Luteum; Estradiol; Female; Humans; Luteolytic Agents; Norandrostanes; Progesterone

Anordrin has been used as an effective postcoital contraceptive in China. The mechanism of anordrin and its analogue SIPPR-113 on antifertility has been studied. Anordrin and SIPPR-113 possessed estrogenicities and induced decrease in serum progesterone levels in rats. Their antiprogesterone activities might be mainly caused by their estrogenicities, which were the main but not the only contributors for the antifertility. The direct effects of anordrin and SIPPR-113 on human trophoblast cells were studied. A concentration of 50 micrograms/ml or 100 micrograms/ml of anordrin or SIPPR-113 could injure the human trophoblast cells in vitro. The uterine Pontamine blue reaction of mated rats was inhibited in those treated with anordrin or SIPPR-113 at the dose of 4 mg/kg. Anordrin, SIPPR-113 or AF-45 was given orally, intramuscularly and intravenously. The effects of drugs administered via the three routes were nearly the same. This study further demonstrated that anordrin was hydrolyzed to break its bond of dipropionate and was transformed into its parent steroid AF-45 to exert its antifertility effects in vivo. This study warrants that anordrin should been evaluated further.

Topics: Administration, Oral; Animals; Azo Compounds; Biotransformation; Endometrium; Female; Humans; Injections, Intramuscular; Injections, Intravenous; Norandrostanes; Pregnancy; Progesterone; Rats; Rats, Inbred Strains; Trophoblasts; Trypan Blue

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