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PubMed1979

Accumulation of ethinylestradiol in blood and endometrium of women taking oral contraceptives: the sequential therapy.

A radioimmunoassay to quantitate ethinylestradiol (EE-2) in both plasma and endometrium is described. In 29 women under sequential oral contraceptive therapy (chlormadinone acetate, 2 mg, plus mestranol, 80 microgram) for 6 to 84 months, a single blood sample and a single endometrial sample were simultaneously obtained on different days of the pseudomenstrual cycle. In 24 women under 40 years of age the mean plasma EE-2 concentrations were similar during the first (989 +/- 94 pg/ml) and the second half of the cycle (1053 +/- 186 pg/ml) (P greater than 0.05). A similar finding was observed with regard to mean endometrial EE-2 concentrations (3.55 +/- 2.1 and 5.89 +/- 1.7 microgram/gm of wet tissue, respectively). On the other hand, five women over 40 years of age had plasma EE-2 concentrations similar to those of the previous group, but the mean endometrial EE-2 concentrations was 0.9 +/- 0.6 microgram/gm of wet tissue (P less than 0.05). Although plasma follicle-stimulating hormone and luteinizing hormone did not show midcycle peak values, complete suppression of both gonadotropins was not observed. These results show that endometrium has a great ability to concentrate EE-2, and this ability seems to be greater in women below age 40 than above. Whether or not this observation might be related to the known higher incidence of endometrial cancer in women less than 40 years old who have been under chronic sequential oral contraceptive therapy cannot be disclosed from this limited number of determinations.

Adolescent↗
PubMed1976

Biliary metabolites of estriol in the rat.

Following the subcutaneous administration of estriol-6,7-3H to rats, biliary metabolites were identified and quantitated. Approximately 70% of the metabolites were excreted in the form of "glucosiduronate" conjugates. 3,17beta-Dihydroxy-2-methoxy-1,3,5(10)-estratrien-16-one was the major metabolite in this conjugate fraction. Significant amounts of 3,17beta-dihydroxy-1,3,5(10)-estratrien-16-one and 2,3,17beta-trihydroxy-1,3,5(10)-estratrien-16-one, as well as smaller quantities of 1,3,5(10)-estratriene-2,316alpha,17beta, tetrol and 2-methoxy-1,3,5(10)-estratriene-3, 16alpha, 17beta-triol, were also found. In 17alpha-ethinylestradiol-treated animals, the rate of excretion of radioactivity and the proportion of 16-oxo-17beta-ol metabolites found in the "glucosiduronate" fraction were reduced.

Animals↗
PubMed1992

Existence of multiple peaks in plasma ethinyl estradiol and norethindrone after oral administration of a contraceptive pill.

Previous measurements of plasma ethinyl estradiol (EE2) and norethindrone (NE) over 24 h after oral administration of a contraceptive pill have demonstrated a single steroid peak occurring 1-2 h after pill ingestion, with a gradual decline over the next 22 h. In the present study plasma concentrations of EE2 and NE were measured 0, 0.5, 0.75, 1, 2, 4, 12, and 24 h after oral ingestion of a contraceptive pill containing 35 micrograms EE2 and 1 mg NE at 0, 3, 6, and 9 months of use in 58 normal healthy women. Contrary to previous reports, analysis of the 464 steroid curves (58 subjects x 4 time periods x 2 steroids) revealed the presence of multiple hormone peaks. Two peaks of EE2 were identified in 44.8% of women during the first pill cycle and in 75.9%, 55.2%, and 67.2% of women after 3, 6, and 9 months of pill use. Two hormone peaks of NE were observed in 29.3% of women during the first cycle and in 36.2%, 50%, and 44.8% at 3, 6, and 9 months, respectively. Existence of these multiple peaks at the frequency observed has not previously been reported. Further quantification of the frequency and magnitude of these peaks could be helpful in explaining differences in biological responses associated with pill use.

Adult↗
PubMed1975

[The experimental studies on the estrogenic activities of 17alpha-ethynyl-17beta-hydroxy-19-norandrost-4-en-3-one (ENT) (author's transl)].

Today, ENT is a popular synthetic progesteron for clinical use, and is well known to have some estrogenic activity. Estradiol-17beta (E2) or 17alpha-ethynyl estradiol (EE2) binding to the specific protein in the nuclear fraction of hypothalamus were examined by 3H-E2 exchange assay reported by Anderson. The possible mode of the estrogenic actions of ENT are as follows: 1) Conversion of ENT to EE2. 2) Estrogenic of ENT per se without changing the chemical structure. 3) Conversion of ENT to other estrogenic compounds except for EE2. In this experiment, 3H-ENT or 3H-testosterone (3H-T) was incubated with human placental microsomes and NADPH generating system for 1 hr at 37 degrees C, 3H-delta4AD, 3H-T and 3H-ENT were incubated also with homogenates of rat hypothalamus under the same conditions. Isolation and purification of the metabolites were performed by using phenolic separation and paper chromatography. Identification of EE2, a metabolite of ENT, was established by measuring the radiochemical homogenity with the authentic standard on paper chromatography. In another experiment where alkali was not used during the extraction procedure to avoid making artificial products, the conversion rate of ENT to EE2 was measured. This experimental data indicated that ENT was converted to 1beta-OH-ENT and to EE2 by human placental microsomes. The former compound was easily converted to EE2 in the presence of NaOH or by incubation with bile. In the incubation with hypothalamic preparation neither aromatization nor 1beta-hydroxylation of delta4AD, T and ENT were detected. In the exchange assays of E2 receptor, the animals were killed 1 hr after the administration of 25 mug of various steroids. The hypothalamic nuclear fraction was incubated with various 3H-steroids for 30 min at 37 degrees C. After washing this nuclear pellet, the radioactivity was counted. Administration of E2 in vivo resulted in the increase of the amount of 3H-EE2 bound to the nuclear fraction in vitro. But only a small increase of binding was observed in the similar experiment with 3H-ENT. 3H-EE2 was exchanged more abundantly after ENT administration than after EE2 injection. From the above results, it was concluded that the estrogenic effect of ENT is attributed to the EE2 converted in vivo. In addition, a possibility was proposed that ENT or its metabolites other than EE2 could regulate some step in the mechanism of estrogen action.

Androstenedione↗
PubMed1977

Oestrogenic activity of oestradiol-decanoate after oral administration to rodents.

Oestradiol-decanoate, dissolved in arachis oil and orally administered to rodents, produces oestrogenic effects. Compared on a molecular basis the ester has 0.1-1.0 times the activity of ethinyl oestradiol, dependent on the species and the parameter studied. The effects of oestradiol-decanoate are less or absent when the oil is omitted. It is likely that absorption of the steroid ester takes place via the intestinal lymphatics in conjunction with the oil.

Administration, Oral↗
PubMedDate not supplied

Radioimmunoassay of norethindrone (17 alpha-ethynyl-17 beta-hydroxy-4-estren-3-one) and ethynyl-estradiol (17 alpha-ethynyl-1,3,5, (10)-estratien-3, 17 beta-diol). Application to human plasma determination of norethindrone after oral administration of this steroid.

The experiment conditions for the evaluation of Norethindrone (17 alpha-Ethynyl-17 beta-hydroxy-4-estren-3-one, NET) and Ethynyl-estradiol (17 alpha-ethynyl-1, 3, 5 (10) estratrien-3, 17 beta-diol, EE) by radioimmunoassay are described. A minimal quantity of 25 pg of these two steroids could be evaluated using different reduced metabolites of NET, very little cross reaction is observed with 200 pg of these metabolites. No effect was observed with estradiol for the EE-antiserum. The NET-antiserum was used to evaluate this steroid and ethynodiol diacetate after oral administration to female volunteers. Maximal values in the plasma (2-3% of the administered dose) was found between 1-3 h after administration and at 24 h a concentration of 0.1-0.3% still remained in the plasma.

Administration, Oral↗
PubMed1975

[Plasma concentrations of LH and of sex steroids during the normal menstrual cycle and during contraceptive treatment].

The authors have studied the long-term effects of combined oestrogen-progestogen on the secretion of gonadotrophins and on ovarian function. Estimation of the radio-immune levels of the plasma concentrations of the pituitary luteinizing hormone (LH), of oestradiol (E2), of progesterone (P) and of 20 alpha hydroxyprogesterone (20 alpha OHP) and of testosterone (T) served as a base for this study. A test cycle and 8 cycles in which a combination of 50 micrograms of ethinyl-oestradiol and 0.5 mg of norgestrel were administered were studied in 4 normal volunteer women. A pituitary stimulation test using 50 micrograms of gonadotrophin "releasing factor" (LH-RH) was given during the 7th cycle. Ovarian stimulation using human menopausal gonadotrophins (HMG) was given during the 8th cycle of treatment in 3 of the women and in 3 other subjects. Pituitary secretion of LH and ovarian secretion of E2 and P are partially inhibited. Pituitary response to the injection of LH-RH stays normal but 5 out 6 patients had no response to stimulation by gonadotrophins. These results allow us to conclude that the lowering of production of gonadotrophins during treatment with combination oestrogen and progestagens is responsible for inhibition of ovarian activity, and that there is a delay before the latter respond to stimulation by either endogenous or exogenous gonadotrophins.

Adult↗
PubMed1977

Serum levels of d-norgestrel, luteinizing hormone, follicle-stimulating hormone, estradiol, and progesterone in women during and following ingestion of combination oral contraceptives containing dl-norgestrel.

Three formulations of dl-norgestrel were administered daily to groups of three women for five consecutive days. The serum levels of d-norgestrel were related to the dosage of dl-norgestrel ingested. Peak concentrations in the circulation of synthetic gestagen were attained a half hour to three hours after oral administration, followed by a rapid and sharp decline in levels until the next dose. Three women received 500 micrograms of dl-norgestrel and 50 micrograms of ethinyl estradiol for 21 days followed by six to seven days of no medication for two consecutive cycles. The gonadotropins remained suppressed for four to six days when therapy was discontinued. The daily concentrations of estradiol varied from less than 5 to 81 pg. per milliliter, and there was no difference in estrogen values during the nontreatment and treatment days. Due to the long half life of norgestrel, the one-week pill-free interval is not long enough for the complete recovery of the reproductive axis from the inhibition of oral contraceptives.

Adult↗
PubMed1978

Factors affecting pituitary gonadotropin function in users of oral contraceptive steroids.

In order to determine whether certain factors influence the direct pituitary suppressive effect of contraceptive steroid, 50 subjects who had used various formulations of oral contraceptive steroids for periods of time ranging from one to nine years were stimulated with 50 microgram of gonadotropin-releasing hormone (GnRH) during the last week of oral contraceptive ingestion. The response of lutinizing hormone (LH) and follicle-stimulating hormone (FSH) was compared to the results obtained in nine control subjects with regard to: (1) age of subject. (2) type of contraceptive formulation used, and (3) length of use. Prestimulation levels of LH and FSH, respectively, were significantly decreased in 37 (74 per cent) and 42 (84 per cent) of the subjects. Following GnRH stimulation, peak responses of serum LH and FSH, respectively, were also significantly lower than those in the control subjects in 40 (80 per cent) and 45 (90 per cent of the subjects. The degree of suppression of pituitary gonadotropins, both before and after GnRH administration was significantly correlated with the type of steroid formulation used, being greatest with a combination of d-norgestrel and ethinyl estradiol. No correlation was found with length of use of oral contraceptives or age of the subjects.

Adult↗
PubMed1977

In vitro steroid metabolic studies in human testes I: Effects of estrogen on progesterone metabolism.

A technique of incubation of testicular tissue in vitro with radiolabeled precursors was applied in the investigation of the steroid biosynthesis by testes of four young men after long-term, high-dose estrogen treatment. A positive correlation between plasma and testicular steroid levels, and in vitro capacity of the testes to metabolize progesterone was demonstrated. Estrogen administration produced a very significant inhibition of plasma and testicular levels of testosterone. The in vitro synthesis of testosterone from progesterone was very severely impaired; especially 17alpha-hydroxylation of progesterone. 20alpha-hydroxysteroid-dehydrogenase activity was found to be increased after estrogen treatment, both in vivo and in vitro. These findings suggest that testicular 17alpha-hydroxylase activity (and possibly also 17-20 lyase activity) is either under gonadotropin regulation, or is directly suppressed by estrogen. This could result by decreased enzyme synthesis, direct enzyme inhibition or affectation of the cofactors or cytochromes necessary for the enzymatic activity. 20alpha-reduction of C21-steroids would represent an alternative pathway for their catabolism, not regulated by gonadotropin or not affected by estrogen, that would be significant in situations with reduced 17alpha-hydroxylase activity.

Adult↗
PubMed1978

Serum levels of FSH, LH, estradiol-17 beta and progesterone following the administration of a combined oral contraceptive containing 20 micrograms ethinylestradiol.

An oral contraceptive containing 20 micrograms of ethinylestradiol and 250 micrograms of levonorgestrel was given to 5 normally menstruating women for two consecutive cycles. Peripheral serum levels of FSH, LH, estradiol-17 beta and progesterone were determined during the treatment period and during two control cycles, one immediately before, and one immediately after treatment. In all 5 women studied there were no LH peaks and no luteal phase levels of progesterone during the treatment cycles indicating complete inhibition of ovulation. 4 of the 5 women showed no biphasic estradiol pattern. Posttreatment control cycles showed reestablished ovulatory pattern in 4 of the 5 subjects.

Adolescent↗
PubMed1992

Comparative contraceptive efficacy and mechanism of action of the norgestimate-containing triphasic oral contraceptive.

Norgestimate (NGM), a derivative of 19-nortestosterone with very specific affinity for the progesterone receptor, has been used in combination with ethinyl estradiol (EE) at low doses in both monophasic and triphasic oral contraceptives (OCs). An open-label comparative clinical trial was conducted with 4,234 healthy women using comparative clinical trial was conducted with 4,234 healthy women using triphasic levonorgestrel (LUG)/EE and NGM/EE through a total of 22,312 menstrual cycles. Contraceptive (LUG)/EE and NGM/EE through a total of 22,312 menstrual cycles. Contraceptive efficacy was excellent with both preparations, with no statistically significant between-regimen differences in pregnancy rates. The theoretical Pearl index was the NGM/EE triphasic, and 0.34 for the LNG/EE triphasic. Adverse experiences in groups were typical of those that may occur among women taking low-dose OC agents. was similar with the two preparations: 8.6% for the NGM/EE triphasic and 6.8% for the LNG/EE triphasic. In a separate mechanism of action study, specific endocrine parameters were investigated in 20 subjects using the NGM/EE triphasic for 4 cycles. Ovulation suppression was demonstrated in statistically significant decreases from pretreatment values in serum levels of luteinizing hormone, follicle-stimulating hormone, progesterone, and estradiol. Significant on-treatment increases in serum levels of sex hormone binding globulin evidenced minimal androgenicity. All hormonal values returned to or toward normal in the post-treatment cycle. The study results support those obtained in large noncomparative studies of the NGM/EE triphasic. This phased-dose combination suppresses ovulation and is a very effective, minimally androgenic contraceptive agent with a good safety profile.

Adolescent↗
PubMed1979

Estrogen and progestin regulation of the progesterone receptor concentration in human endometrium.

The concentration of the progesterone receptor (PR), both cytosol and nuclear, has been measured in the endometrium of 31 normal menstruating women during the 2 phases of their menstrual cycle and compared with the plasma 17 beta-estradiol and progesterone concentrations. There was no relationship between PR concentrations and the plasma steroid levels when the 2 phases of the cycle were considered; however, a statistically significant correlation (r = 0.70; P less than 0.005) was observed between PR concentration and plasma 17 beta-estradiol when only the follicular phase was considered. PR was then measured in the endometrium of 14 postmenopausal patients treated with ethinylestradiol at increasing doses with or without association of chlormadinone acetate. Ethinylestradiol was shown to increase PR concentration (P less than 0.05), and chlormadinone acetate was found to prevent this increase. These data suggest that in humans, as in other mammalian species, the endometrial PR concentration is under estrogen and progestin control.

Chlormadinone Acetate↗
PubMed1992

Hormone levels and anogenital swelling of female chimpanzees as a function of estrogen dosage in a combined oral contraceptive.

A combined oral contraceptive consisting of ethinyl estradiol (EE2) in three dosages (50, 100, and 400 micrograms) and norethindrone (0.5 mg) was given to female chimpanzees to determine the effect on endogenous sex hormone levels and anogenital swelling. Serum levels of EE2 increased with increasing dosages of EE2, estradiol decreased, and luteinizing hormone, progesterone and testosterone were maintained at approximately midfollicular phase levels. Urinary levels of EE2 glucuronide increased with the increasing dosages of EE2, whereas estrone and pregnanediol glucuronide were essentially undetectable. The cyclic increase in female anogenital swelling was abolished when the norethindrone was combined with 50 micrograms of EE2 and relatively constant and low levels of swelling were recorded. Relatively constant but successively higher levels of swelling were recorded when the norethindrone was combined with the higher dosages of EE2. These effects of oral contraceptives on female genital tissues are relevant to our laboratory studies of sexual behavior in chimpanzees given oral contraceptives and could also have implications for women taking oral contraceptives.

Anal Canal↗