Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00691 (EE2)
 7,802 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Gonadectomized male and female rats were treated with equimolar doses of estradiol benzoate (EB) and testosterone propionate (TP) daily for periods of 3 days to 1 week and activities of monoamine oxidase (MAO) and choline acetyltransferase (ChAc) were measured in the cortex, hippocampus, basomedial hypothalamus, corticomedial amygdala and medial preoptic areas. After hormone treatment, changes in enzyme activities were found in those brain regions where gonadal hormones are known to affect sexual behavior and/or gonadotropin release and which contain putative hormone receptor sites. More specifically, EB administration to females resulted in decreased activity of MAO in the corticomedial amygdala and basomedial hypothalamus and an elevation of ChAc activity in the medial preoptic area and corticomedial amygdala while TP administration did not alter enzyme levels in any brain region. In contrast, EB administration to castrated males was without significant effect on enzyme activities while TP administration resulted in increased activity of MAO and ChAc in the medial-preoptic area. The estrogen antagonist, MER-25, given concomitantly with EB, effectively blocked EB-dependent changes in both enzymes in ovariectomized female rats. EB treatment to hypophysectomized females led to similar enzymatic changes as in ovariectomized females in all areas except the basomedial hypothalamus. Estradiol added directly to the enzyme incubation medium did not result in altered enzyme activities. Results obtained are discussed in relation to sexual differentiation of the brain, metabolism of gonadal hormones, and possible mechanism of gonadal hormone regulation of enzyme activities.
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PMID:Effect of gonadal steroids on activities of monoamine oxidase and choline acetylase in rat brain. 111 99

Norethisterone-3-oxime (NETO) was administered to 3 female cynomolgus monkeys intragastrically and, after a wash-out period of 2-5 weeks, intravenously at a dose of 1 mg/kg. The radioactive dose of tritiated NETO was 20 microCi/kg for both treatments. For i.v. injection, a 30% propylene glycol/water solution and for i.g. administration an aqueous microcrystalline suspension was used. Excretion of radiolabel in urine and feces was followed for 5 days and plasma samples were obtained up to 2 days after administrations. In all samples (urine, feces and plasma) radioactivity was determined. Extracts from plasma samples were subjected to HPLC separation of drug and metabolites, as well as NETO and NET (metabolite of NETO after hydrolysis of the oxime group) levels were determined. In addition, EE2 (ethinylestradiol, A-ring aromatised metabolite of NET) levels were estimated using a specifically designed HPLC system for separation. Quantification of EE2 was achieved by radioimmunoassay (RIA) of specific eluate fractions. The results demonstrate that [3H]-NETO was absorbed completely at a dose level of 1 mg/kg, and excreted predominantly via the kidneys. A urinary to fecal excretion ratio of 1.5 (i.v.) or 1.0 (i.g.) was found. Renal excretion of total radiolabel proceeded with a half-life of about 0.8 (i.v.) or 1.1 (i.g.) days. Balances were incomplete, probably due to technical reasons. Orally administered NETO was highly bioavailable (84.0 +/- 16.9% of dose) but rapidly cleared from plasma (total clearance corresponded to 97% of plasma liver flow). The clearance from plasma is equivalent to the metabolic clearance because almost no unchanged NETO is excreted. Extensive metabolism of the parent drug was observed leading to at least two pharmacologically active metabolites (NET, EE2). The main progestogenic metabolite was NET reaching similar high plasma levels as NETO. EE2 turned out to be a metabolite of NETO and a conversion rate of below 0.5% of dose was estimated. However, due to its high estrogenic potency EE2 might contribute to the overall pharmacological pattern of NETO in the cynomolgus monkey.
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PMID:Pharmacokinetics, hydrolysis and aromatisation of norethisterone-3-oxime in female cynomolgus monkey. 130 58

The aim of this study was to overtake the mechanism of the control system in endometrial cancer cell line in vitro. Ishikawa cell (IK cell) and HEC-1 cell (HEC cell) derived from endometrial cancers were cultured with serum free medium (SFM-101). IK cell possessed Estrogen receptor (ER), Progesterone receptor (PR), Epidermal growth factor (EGF) and its receptor (EGFR). HEC cell had PR, EGF, and EGFR, however HEC cell did not keep ER. EGF stimulated the growth of IK cell, but the growth of HEC cell was not stimulated by EGF. S phase cells were increased by EGF in IK cell, but were not increased by EGF in HEC cell. The growth of IK cell was stimulated significantly by EGF and Estradiol-17 beta (E2) +EGF than control. However, E2+EGF did not stimulate the growth of IK cell than EGF significantly. Danazol (D) and D+EGF inhibited the growth of IK cell significantly than control. S phase cells were decreased by the treatment of D and D+EGF. From our results, EGF stimulated the growth of ER positive endometrial cancer cell, but EGF did not stimulate ER negative endometrial cancer cell. E2+EGF and EGF stimulated the growth of IK cell as a same. However, D inhibited the growth of IK cell that was stimulated by EGF.
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PMID:[Cell cycle analysis of endometrial cancer cells in vitro treated with growth factor and steroid hormone]. 130

The effect of norethindrone acetate (NET-Ac) and ethinyl estradiol (EE2) on the 3 beta-hydroxysteroid dehydrogenase (HSD)-delta5-isomerase complex of the human fetal testis was studied by administration of 20 mg NET-Ac and 0.04 mg EE2 p.o on a single day to 4 women, pregnant 10-16 weeks, before abortion was induced, the other 4 patients serving as controls. Testosterone and androstenedione formation from radioactive dehydroepiandrosterone was measured in 8 fetuses by incubation of testicular tissue in vitro. The presence of normal feta Leydig cells was confirmed by electron microscopy. There was no difference between the enzyme activities of testicles in the experimental and control groups. The findins give values of 3 beta-HSD-isomerase activity in human fetal testis and suggest that the steroidogenic function of the fetal testis exposed for a short time to normally used contraceptive steroids remains at the same magnitude.
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PMID:Androgen synthesis in human fetal testis exposed in utero to a combination of norethindrone acetate and ethinyl estradiol. 181 50

Five synthetic progestins of the 19-nortestosterone type (norethisterone, NET; levonorgestrel, LN; gestodene, GEST; NET-3-oxime, NETO; norgestimate, NGM) were investigated in the in vitro hepatocyte model. Radiolabelled progestins were added to hepatocyte suspensions (3 x 10(6) cells/ml) freshly prepared from female rat, guinea pig, rabbit, dog (beagle) and cynomolgus monkey. Drug level decreases (NET, LN, GEST) and prodrug conversions (NETO, NGM) were followed by radiochromatography (HPLC) for 60 min. In the case of NET and NETO the conversion into ethinyl estradiol (EE2) was quantified by RIA after HPLC separation. Half-lives of drug level decreases (t1/2), areas under the curves (AUC) and metabolic clearance rates (MCR) were estimated for all progestins. For NETO and NGM the percentages of conversion into NET and LN were calculated, respectively, and levels of EE2 determined in the case of NET and NETO. Rat hepatocytes showed an extremely high metabolic activity towards NET, LN and GEST resulting in t1/2 values of below 2 min. Respective values for rabbit hepatocytes ranged from 5-8 min, whereas half-lives calculated for liver cells from guinea pig, dog and monkey were generally above 30 min. A drastic increase in t1/2 was found for NETO (as compared to NET) in hepatocytes from rat, rabbit and monkey but not from guinea pig. Dog hepatocytes degraded NETO about 3 times more rapidly than NET. NGM was degraded much faster than LN in hepatocytes from all species except the rat. Liver cells from guinea pig and dog seem to be able to metabolize the 3-oxime group much more rapidly than hepatocytes from the other animal species. The lowest degree of prodrug conversion of 4% was observed for NGM and dog hepatocytes. Elevated EE2 levels were found in all experiments with NET and NETO. Results of NET, LN and GEST were compared with published in vivo experiments. No correlations were found for t1/2, MCR, and AUC.
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PMID:Investigations on the in vitro metabolism of five synthetic 19-norprogestins using hepatocyte suspensions isolated from five laboratory animal species. 193 77

Oral contraceptives have the highest theoretic efficacy of all reversible forms of contraception, yet in practice they have an actual failure rate equivalent to that of some barrier methods. The efficacy of oral contraceptives depends primarily on patient compliance. So-called "nuisance" side effects, such as intermenstrual bleeding (breakthrough bleeding or spotting), play a major role in their discontinuation. The Triphasic Randomized Clinical Trial compared the incidence of these side effects in three groups of subjects taking NET (A) (Ortho-Novum 7/7/7), LNG (Tri-Levlen), or NET (B) (Tri-Norinyl). Subjects taking NET (A) had the highest incidence of intermenstrual bleeding (63%) followed by NET (B) (44%) and LNG (33%). Only the difference between NET (A) and LNG attained statistical significance (p less than 0.030). Control subjects had no breakthrough bleeding and a 4% incidence of spotting. Further research is warranted to establish the cause of the disparity in the incidence of intermenstrual bleeding among patient groups assigned to the three oral triphasic contraceptives.
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PMID:Triphasic Randomized Clinical Trial: comparative frequency of intermenstrual bleeding. 268 57

In a double-blind randomized trial, 25 women (8-9 weeks pregnant) received 20 mg norethisterone acetate (NET-AC) and 0.04 mg ethinylestradiol (EE2), 25 women receiving placebo. The patients were followed by ultrasound and the products at curettage studied macroscopically and microscopically. In an open trial, ten patients (5-9 weeks pregnant) received NET-AC + EE2, 11 serving as controls. The concentrations of plasma progesterone, estradiol-17 beta, 17 alpha-hydroxyprogesterone, norethisterone, and FSH were followed. The frequency of intrauterine hemorrhage in early pregnancy was not affected by NET-AC + EE2. Ultrasound was not reliable when studying the occurrence of decidual hemorrhages during early pregnancy. The pharmacokinetics and bioavailability of NET remain unchanged during early pregnancy. The treatment with NET-AC + EE2 had no effect on the heights and the time courses of the mean plasma values of progesterone, estradiol-17 beta, 17 alpha-hydroxyprogesterone, and FSH. No differences were found between treated and nontreated patients in the pathology of the placenta or decidua as determined by both macroscopic and microscopic examinations. The hypothesis of Papp and Gardo, that decidual hemorrhages may be induced in early pregnancy as a consequence of a "withdrawal effect" of hormonal pregnancy tests, is not supported by the results of this investigation.
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PMID:Norethisterone acetate and ethinylestradiol in early human pregnancy. 642 76

The time course of the concentration of the 14C- and 3H-labelled substances and of unchanged norethisterone was determined in maternal plasma and selected tissues of the feto-placental unit after intragastric administration of a combination of 14C-norethisterone acetate (NET-Ac) and 3H-ethinylestradiol (EE2), respective commercial formulation: Ostro - Primolut , to pregnant rats. When given intragastrically in doses of 1 mg NET-Ac/kg and 0.002 mg EE2/kg both synthetic steroids were rapidly and completely absorbed. Highest concentrations of 14C-labelled substances were measured 0.5 h p. admin . in maternal and fetal tissues. Only approximately 1% of total radioactivity in maternal plasma (= 30 ng NET/ml) corresponded to unchanged norethisterone. Less than 1% of the dose administered passed the placental barrier. The maximum NET-levels in the fetuses amounted to 4 ng NET/g tissue. The highest levels of EE2-metabolites in the fetuses were found 2-5 h after administration with 34 pg EE2-equiv./g corresponding to only 0.15% of the dose administered in total fetuses. 14C- and 3H-radioactivity was eliminated from the fetuses with a similar or only a slightly lower rate than from the maternal organism. When administered intragastrically the twofold dose (2 mg NET-Ac/kg plus 0.004 mg EE2/kg) to pregnant rhesus monkeys maximum NET plasma levels of 40 ng/ml were observed after 2 h. Thereafter the NET plasma levels decreased with a half-life of 1.4 hours. The time course of NET concentrations in ovary and pituitary mirrored plasma levels whereas that in placenta and amniotic fluid paralleled plasma levels at a 30-50% and 3-15% niveau , respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Distribution of norethisterone and ethinylestradiol in the gravid rat and in the feto-placental unit of rhesus monkeys following intragastric administration of norethisterone acetate in combination with ethinylestradiol. I. Direct determinations. 654 Jan 2

The tissue distribution of 14C- and 3H-radioactivity was studied in pregnant rats and in fetuses of rhesus monkeys after intragastric administration of a combination of 14C-norethisterone acetate (14C-NET-Ac; 1 mg/kg rat, 2 mg/kg rhesus monkey) and of 3H-ethinyl-estradiol (3H-EE2; 2 micrograms/kg rat, 10 micrograms/kg rhesus monkey), respective commercial formulation: Ostro-Primolut, by means of autoradiographic methodology. The results of these present investigations confirm quantitative studies of a low, transitory passage of 14C-NET-Ac and 3H-EE2 into the fetuses. Within the fetuses the highest concentrations of 14C-radioactivity were found in the liver, in the vertebra, in heart and brain. No 3H-radioactivity could be observed within the fetuses. The autoradiographic studies do not indicate any specific enrichment of NET-Ac or EE2 and their metabolites in fetal organs and tissues.
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PMID:Distribution of norethisterone and ethinylestradiol in the gravid rat and in the feto-placental unit of rhesus monkeys following intragastric administration of norethisterone acetate in combination with ethinylestradiol. II. Autoradiography. 654 May 77

Twenty-four normal adult female volunteers were dosed orally with a solution and tablet formulation containing the contraceptive combination of norethindrone (NET, 1.0 mg) and ethinylestradiol (EE2, 0.12 mg) in a crossover bioequivalence study. Blood was sampled sequentially following single oral doses and the plasma separated for analysis of NET and EE2 by specific radioimmunoassays. Comparisons of both drugs following a dose in solution and tablets were made with respect to the following parameters: (a) plasma concentrations at each sample time; (b) maximum plasma concentration (Cpmax); (c) time to maximum plasma concentration (Tmax); (d) total area under the plasma concentration vs. time curve (AUC), and (e) plasma half-life (t1/2). It was found that the tablet and solution doses were bioequivalent with respect to EE2 absorption. However, absorption of NET from solution and tablet doses exhibited significant differences with respect to plasma levels at certain time points as well as AUC (which were higher following the tablet dose), but Cpmax, Tmax and t1/2 were not significantly different. Pharmacokinetic analysis of both drugs following the tablet dose was carried out using a two-compartment open model. The absorption rate constant (ka) and peripheral to central compartment transfer rate constant (k21) were similar for NET and EE2, but statistically significant differences were observed with respect to the distribution rate constant (alpha), the central to peripheral transfer rate constant (k12), the overall elimination rate constant (ke1), and volume of distribution (V1/F). The elimination rate constant (beta) for both drugs showed a difference of borderline statistical significance.
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PMID:Plasma levels and pharmacokinetics of norethindrone and ethinylestradiol administered in solution and as tablets to women. 664 Dec 24


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