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Results for “Estrogens--analysis”

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At least 19 recordsLinked to original sources
PubMed1979

New long-acting injectable microcapsule contraceptive system.

A new long-acting, injectable contraceptive which provides continuous controlled release of the steroid norethisterone (NET) for a precise period of 6 months following a single intramuscular injection is described. The prototype system consists of microcapsules made of the biodegradable polymer d, l-polylactic acid, in which micronized crystals of NET are homogeneously dispersed. NET is slowly released from the microcapsules following intramuscular injection at a rate of 0.90 microgram NET/day/mg of microcapsule by diffusion of the steroid from the polymer matrix. Three different doses of a standard preparation of microcapsules were tested in normally cycling female babbons (4 to 5 baboons/group). Following injection of either 300, 200, or 100 mg of microcapsules containing 75, 50, or 25 mg of NET, blood samples were collected at selected intervals and analyzed for NET, estrogen, and progesterone by radioimmunoassay. All three doses provided continuous NET release for 6 months following injection. The NET serum profiles for the different doses are parallel, and ovulation was inhibited in all baboons for 6 months following treatment.

Animals↗
PubMed1976

Estrogen biosynthesis and 1beta-hydroxylation using C19 and 19-nor steroid precursors.

(1) In order to study the relationship between aromatization (estrogen biosynthesis) and 1beta-hydroxylation, the effects of a variety of factors on these processes were evaluated. (2) Using the C18 substrate, 4-estrene-3,17-dione, it was found that carbon monoxide, SU-4885, amphenone B, potassium cyanide, 4-androstene-3,17-dione and 1,4-androstadiene-3,17-dione inhibited the above transformations significantly and to varying degrees. However, within a given experiment the inhibition of each process was similar. (3) SKF-525A did not inhibit either transformation. In addition, phosphate, Tris and barbital buffers, as well as pH changes from 6.9 to 7.7, had no stimulatory or inhibitory effect on the production of estrogen and 1beta-hydroxy compounds. (4) In contrast, several inhibitors affected the aromatization of C19 and C18 steroids differently. These include carbon monoxide, SU-4885 and amphenone B. (5) When a mixture of 4-[7beta-3Hi1estrene-3,17-dione and 19-[4-14C]nortestosterone were incubated together the former was preferentially converted to estrogen. This preference for the 17-keto steroidal form mimics results observed for C19 substrates. (6) We conclude that while estrogen biosynthesis and 1beta-hydroxylation appear to be mediated by the same enzyme system, the same conclusion cannot be drawn for the aromatization of C19 and C18 substrates.

Buffers↗
PubMed1978

The preparation of pregnancy urine for an estrogen profile.

A method is described for purifying the estrogen content of pregnancy urine with little loss of the labile estrogens. The procedure makes use of the initial 50-fold purification effected by their precipitation whith ammonium sulphate, with simultaneous elimination of most urinary corticosteroids and 50--60% of urinary ketosteroids. It also employs the antioxident ascorbic acid as an additive in most stages of the procedure. The mild organic-solvent-HIO partition system of Brown is used for separating the strongly polar, 2including all "labile" estrogens, and of the weakly polar estrogens, from neutral steroids. The remaining neutral steroid still interfering with the assays were removed by an ascorbic acid treated ion exchange resin (AG 1). The final residues were revealed by mass-spectroscopy to consist almost solely of estrogens. Gas-liquid chromatography in which just 2 chromatograms are required yields a total of 12 "estrogen" peaks (for 12 estrogens which are excreted in amounts greater than 0.1 mg/day) in normal pregnancy urine, including all the known labile estrogens. Identification as estrogen for all but a few minor peaks of the gas chromatogram was obtained by mass-spectroscopy. The practical significance of the method lies in the fact that some labile estrogens are much more important in the estrogen metabolism of pregnant and nonpregnant women than heretofore generally thought.

Ammonium Sulfate↗
PubMed1975

The urinary metabolites of 17alpha-ethynylestradiol-9alpha,11xi-3H in women. Chromatographic profiling and indentification of ethynyl and non-ethynyl compounds.

Metabolites of 17alpha-ethynylestradiol (EE2) were obtained from human urine following ingestion of tritium-labeled EE2. Over 95% of the recovered activity was found as conjugated steroids and these were separated into four groups by chromatography of the urine extract on Sephadex LH-20 with chloroform-methanol (1/1) + 0.01M NaCl. The two major conjugate fractions appeared to be almost exclusively glucosiduronates. Enzymatic hydrolysis liberated at least ten different EE2 metabolites as shown by chromatography on Sephadex LH-20 with benzene-methanol (85/15). After additional separation and purification of these metabolites, positive identification was obtained for nine radioactive compounds by either gas liquid chromatography-mass spectrometry or reverse-isotope recrystallization. Five were ethynyl compounds: EE2, 2-MeO EE2, 16beta-OH EE2, 2-OH EE2 and 6alpha-OH EE2. The other four were de-ethynylated estrogens: estrone, estradiol-17beta, estriol, and 2-Me-O-estradiol-17beta.

Chromatography, Gas↗
PubMed1979

The relation between plasma oestrogen, progesterone and prolactin concentrations and the efficacy of vaginal prostaglandin E2 gel in initiating labour.

In an attempt to relate the efficacy of treatment to endogenous hormone levels, plasma oestrogen, progesterone and prolactin levels were analysed in women at term following the vaginal administration of prostaglandin E2 gel to induce labour. Patients who went into labour after treatment had significantly higher oestradiol-17 beta levels before treatment compared with those requiring formal surgical induction the following day. No difference could be demonstrated in levels of progesterone or prolactin in the two groups of patients. The significance of these results is discussed.

Estradiol↗
PubMed1979

Failure of estrogen-induced discharge of luteinizing hormone in lactating women.

Pituitary-ovarian relationships were studied in seven lactating women by measuring the basal plasma concentrations of pituitary and ovarian hormones and their responses to an estrogen provocation test at 7, 30, and 100 days after delivery. The results were compared to a similar group of seven women who did not breast feed. The first ovulation occurred in five of the nonlactating women beteen 43-87 days after delivery, as judged by the urinary excretion of total estrogen and pregnanediol. In all lactating women, ovarian cyclicity was suppressed for at least 150 days after delivery or until weaning. The basal concentration of PRL in lactating women was significantly higher than in the nonlactating women at all three times measured. At 30 and 100 days, the concentration of estradiol was significantly lower in the lactating women, although the basal concentrations of FSH were similar in the two groups. After an injection of 1 mg estradiol benzoate, the concentrations of FSH and LH in plasma were suppressed to a greater extent in lactating than in nonlactating women. In addition, fewer of the lactating group (one of seven and none of seven at 30 and 100 days, respectively) than the nonlactating group (two of seven and five of seven) subsequently showed a rise in the concentration of LH 58--96 h after the estrogen injection (positive feedback). These results suggest that during lactation the hypothalamic-pituitary system is more sensitive to the negative feedback and relatively insensitive to the positive feedback of estrogen.

Adult↗
PubMed1977

Steroid sex hormones and prolactin in postmenopausal women with generalized mammary carcinoma during prolonged dexamethasone treatment.

The endocrine response to prolonged dexamethasone treatment was investigated in six postmenopausal women with generalized mammary carcinoma. Plasma cortisol levels decreased rapidly and became undetectable whereas significant concentrations of plasma dehydroepiandrosterone and androstenedione persisted throughout the study, even in two ovariectomized patients, indicating a certain degree of autonomy or a greater resistance of adrenal 'androgens' to the inhibition of ACTH secretion. Except in the ovariectomized patients, plasma testosterone did not fall significantly whereas the plasma oestrogens tended progressively towards undetectable concentrations. A similar response was found in six normal postmenopausal women although the disappearance of their oestrogens was relatively rapid. This indicates that much of the testosterone present after the menopause could still be produced by the ovaries whereas the ovarian production of oestrogens becomes negligible. The delayed disappearance of oestrogens in the patients with mammary carcinoma indicates that the persisting adrenal 'androgens' remained efficient precursors of oestrogen synthesis within the peripheral tissues and presumably within the mammary tumour itself. Plasma dihydrotestosterone behaved like the plasma oestrogens. Despite the fall in plasma oestrogens, plasma gonadotrophins did not increase further but plasma prolactin rose progressively. The persistance of steroid sex hormones and the rise of plasma prolactin might explain the poor response to dexamethasone treatment in mammary carcinoma.

Aged↗
PubMed1977

Cyclic fluctuation in noradrenaline transmitter of the monkey oviduct.

Cyclic variations in noradrenaline of the sympathetic nerves ("short adrenergic neurons") innervating the smooth musculature of the oviduct have been determined by fluorescence histochemistry and fluorometric measurements in monkeys (Macaca mulatta). During the secretory phase there is more than twice as much neuronal noradrenaline in the oviduct compared with the proliferative phase. This suggests, that the system of adrenergic nerves in the primate oviduct is involved in the motility changes associated with alterations in the level of endogenous estrogen and progesterone during the menstrual cycle.

Animals↗