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)

Estrogens have been examined in the plasma of diploid and triploid newts Pleurodeles waltlii. Estradiol-17 beta (E2) and estrone (E1) were determined by radioimmunoassay, before and after enzymatic hydrolysis of the conjugates. Total (t) and unconjugated (u) E2 levels were positively correlated (E2u = 0.478 35 E2t + 0.579 98; r = 0.883), but no correlation was detected between E1 levels. No statistical difference was found for the estrogen levels between the different experimental lots of diploid newts (E2t = 7.5 +/- 0.37 ng/ml, E2u = 4.3 +/- 0.20 ng/ml, E1t = 2.19 +/- 0.08 ng/ml, E1t = 0.41 +/- 0.02 ng/ml) but every estrogen level was lower in the triploid group (E2t = 1.8 +/- 0.60, E2u = 1.0 +/- 0.18, E1t = 1.4 +/- 0.13, E1u = 0.3 +/- 0.04 ng/ml). This difference is discussed in relation to lower fertility of the triploid females.
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PMID:[Plasma estrogens in Pleurodeles waltlii. Comparison between diploid and triploid females]. 11 5

The uterotropic and antiuterotrapic effects of a variety of structural derivatives of the nonsteroidal antiestrogen tamoxifen have been determined in the rat and the mouse. One derivative, monohydroxytamoxifen, was found to be a potent antiestrogen in the rat, with a high affinity for the estrogen receptor. Various techniques of sucrose density gradient analysis were used to demonstrate that estradiol and tamoxifen bind to the rat uterine cytoplasmic estrogen receptor. Estrogens and antiestrogens provoke the translocation of estrogen receptors to the nucleus and deplete the cytoplasmic estrogen receptor pool for short or long periods depending on the dose administered. Estradiol stimulates endometrial hyperplasia with an increase in total uterine DNA content, whereas tamoxifen stimulates endometrial hypertrophy with only a slight increase in uterine DNA content. It is concluded that the molecular shape of the ligand that binds to the estrogen receptor determines antiestrogenic activity.
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PMID:Nonsteroidal antiestrogens: their biological effects and potential mechanisms of action. 20 80

The endocrine factors associated with parturient paresis have not been defined totally. Estrogens stimulate uptake of calcium by bone. Since secretion of estrogen increases dramatically as parturition approaches, estrogen may be involved in homeostatic mechanisms regulating calcium metabolism. Plasma was collected for 30 days (-30) prepartum to 5 days (+5) postpartum from six Holstein and nine Jersey cows approaching three or more lactations. Of all cows, six Jerseys contracted parturient paresis. Estradiol and estrone were analyzed by radioimmunoassay, total calcium and total magnesium by atomic absorption spectrophotometry, and total phosphorus by colorimetry. Data were grouped into periods respresenting days -30 to -21, -20 to -11, -10 to -6, -5 to -4, -3 to -2, -1, 0 (parturition), +1, +2 to +3, and +4 to +5. Calcium in plasma was lower in parturient paresis cows on days +1 and +2 to +3, and magnesium was higher during the same periods but lower on days -4 to -5. Total phosphorus, estrone, and estradiol of normal cows and those with parturient paresis were not different. During the entire sampling period, phosphorus and estradiol were similar in both groups while magnesium was higher and calcium lower in cows with parturient paresis. Estrone was lower in cows with parturient paresis. Lower estrone in cows with parturient paresis may be predisposing for parturient paresis.
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PMID:Estrogen in plasma of parturient paretic and normal cows. 45 85

To determine the intratesticular site of aromatization, homogenates of separated seminiferous tubules and intact tissue from human testes were incubated with [3H] androstenedione or [3H] testosterone. [3H] Estrogens were isolated and identified, and the amounts synthesized were expressed as pmol/mg protein incubated. In testicular tissue from the three adult subjects investigated, the total estrogen per mg protein was 1.5-2.7 times greater in intact tissue than in isolated seminiferous tubules. This suggests that the major site of aromatization in human testes is the interstitial tissue. Estradiol was by far the major estrogenic product. No differences were observed in the amount of estrogens synthesized whether the substrate was androstenedione or testosterone.
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PMID:Intratesticular site of aromatization in the human. 93 73

The effect of ENT, a synthetic gestagen, on corpus luteum function in 62 normal and 31 insufficient cycles was studied by radioimmunassay o f plasma levels of progesteorne, immunoreactive estrogens, and gonadotro pins. Doses as high as 100 mg/day immediately after ovulation blocked synthesis of progesterone in normal cycles totally within 4-5 days. Estrogens seemed to be elevated. Smaller daily doses had the same effect, but less pronounced. The effect became weaker with every day after ovulation that therapy was begun. However, a start of therapy on Day 5 after ovulation showed some suppression. 3 tablets daily of a commercial preparation designed for corpus luteum phase defects (100 mcg EE2 and 2 mg ENT per tablet) showed slight suppression of progesterone levels if therapy began close to ovulation but administration during an insufficient luteal phase produced nothing but the expected menstrual delay. This indicates ENT suppresses corpus luteum function by blocking progesterone synthesis exclusively. Plasma levels of estrogens and gonadotropins remained unaltered. The blocking effect depends upon daily dose and age of corpus luteum at start of therapy. Substitution therapy of corpus luteum phase defects in patients with infertility problems should not be used any longer and should never begin earlier than 3 days after ovulation if used at all. Stimulation therapy during follicular phase with clomifene or gonadotropins gives better results.
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PMID:Effects of 17alpha-ethinyl-19-nortestosterone (ENT) on corpus luteum function. 98 42

Estrogens, gestagens, or estrogen-gestagen combinations can be employed as postcoital oral contraceptives. High dose estrogens, such as 5 mg of ethinyl estradiol (EE) daily for 5 days started at the latest 72 hours after unprotected coitus have been proved quite effective with a failure rate of about 1%. However, in about half of the women nausea and in one=third vomiting occurred. Among gestagens the highly effective 19=testosterone preparations are notable. Most experiences pertain to norgestrel (Razemat) as well as to the twice as effective levonorgestrel (D-(-)-norgestrel) LNG. After unprotected coitus, 0.6 mg of LNG taken within 12 hours but possibly even after 1-3 hours is effective. It is common to use a combination of 0.25 mg of LNG and 0/05 mg of EE (Tetragynon). 2 tablets are taken within 48 hours after unprotected intercourse and 2 more 24 hours later. In 4 large studies in Canada and the US with a total of 1540 women who were given instead of LNG the double dose of the half so effective Razemat, the pregnancy rate was 0.9% (14 pregnancies) and the corrected failure rate was 0.65% after excluding women with several unprotected exposures. Assuming a probability of pregnancy of up to 30% after unprotected intercourse depending on the day of the menstrual cycle, the action of the gestagen=estrogen preparation can be regarded as reliable. The side effects are less frequent compared with the high-dose EE therapy. In an Austrian study of 50 women taking Tetragynon, 11 women had nausea, 2 had breast tension, and 4 had vomiting. The duration of bleeding lasted an average of 2 days longer after the taking the pill. 2 women who vomited 2 hours after taking the 1st Tetragynon dose became pregnant. Therefore, in case of nausea it is recommended that an antiemetic be given, and in case of vomiting, the 1st dose of Tetragynon has to be repeated to assure an effective action.
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PMID:[The postcoital pill]. 150 66

Within the framework of experiments related to the association between dietary fiber and breast cancer an in vitro test system was used to study the binding of estrogens to various fibers (e.g. cholestyramin, lignin and cellulose) and fiber sources (e.g. wheat bran, cereals, seeds and legumes). Furthermore, the in vivo apparent digestibility of the different fiber sources was tested using a mobile nylon bag technique in intestine-cannulated pigs. Estradiol-17 beta (E2) bound more strongly to the various fibers than did estrone (E1), estriol or estrone-3-glucuronide. At increasing pH (greater than 7) binding of both E1 and E2 to wheat bran decreased significantly. Cholestyramine and lignin bound almost all estrogens present in the medium. Linseed (91%), oats (83%), barley chaff (88%) and wheat bran (82%) are other excellent binders of E2. Corn, rye and white wheat flour showed lower binding capacity with a relatively low affinity. Cereals with the highest percentage of lignin in the fiber (greater than 3%) were also the fiber sources with the lowest apparent digestibility. Estrogens bound with the highest affinity (relative to bovine serum albumin) to these fiber sources. Together with wheat bran and lignin, oats, linseed and soybean seem to be products with good perspectives for in vivo evaluation of the lowering effect of dietary fiber on estrogen exposure of estrogen-sensitive tissues.
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PMID:In vitro binding of estrogens by dietary fiber and the in vivo apparent digestibility tested in pigs. 164 89

Estrogens have previously been shown to induce DNA damage in Syrian hamster kidney, a target organ of estrogen-induced cancer. The biochemical mechanism of DNA adduction has been postulated to involve free radicals generated by redox cycling of estrogens. As part of an examination of this postulate, we measured the effect of chronic estrogen treatment of hamsters on renal microsomal enzymes mediating catechol estrogen formation and free radical generation by redox cycling of catechol estrogens. In addition, the activities of the same enzymes were assayed in liver in which tumors do not develop under these conditions. At saturating substrate concentration, 2- and 4-hydroxyestradiol were formed in approximately equal amounts (26 and 28 pmol/mg protein/min, respectively), which is 1-2 orders of magnitude higher than reported previously. Estradiol treatment for 2 months decreased 2-hydroxylase activity per mg protein by 75% and 4-hydroxylase activity by 25%. Hepatic 2- and 4-hydroxylase activities were 1256 and 250 pmol/mg protein/min, respectively. Estrogen treatment decreased both activities by 40-60%. Basal peroxidatic activity of cytochrome P-450, the enzyme which oxidizes estrogen hydroquinones to quinones in the redox cycle, was 2.5-fold higher in liver than in kidney and did not change with estrogen treatment. However, when normalized for specific content of cytochrome P-450 the enzyme activity in kidney was 2.5-fold higher than in liver and increased further by 2-3-fold with chronic estrogen treatment. The activity of cytochrome P-450 reductase, which reduces quinones to hydroquinones in the estrogen redox cycle, was 6-fold higher in liver than in kidney of both control and estrogen-treated animals. When normalized for cytochrome P-450, the activity of this enzyme was similar in liver and kidney, but over 4-fold higher in kidney than liver after estrogen treatment. Basal concentrations of superoxide, a product of redox cycling, were 2-fold higher in liver than in kidney. Estrogen treatment did not affect this parameter in liver, but increased it in kidney by 40%. These data provide evidence for a preferential preservation of enzymes involved in estrogen activation.
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PMID:Effect of chronic estrogen treatment of Syrian hamsters on microsomal enzymes mediating formation of catecholestrogens and their redox cycling: implications for carcinogenesis. 216 50

Estrogens are teratogens and developmental carcinogens in several species. We have used uterine growth to quantitate the potency of three estrogens [estradiol (E2), diethylstilbestrol (DES), ethynylestradiol (EE2)] during four postnatal periods (days 1-5, 10-14, 20-24, and 60-64) in the rat. Alphafetoprotein (AFP), present at high levels in neonatal serum, is thought to regulate estrogen bioavailability. Association constants for DES and EE2 were 2.7% and 4.9% of that for E2 binding to AFP, determined in a batch Sephadex equilibrium binding assay. On days 1-5, DES and EE2 were about 80-fold more potent than E2 in increasing uterine weight. As AFP levels fell, potency differences between E2 and the synthetic estrogens decreased. In the adult, which essentially lacks AFP, the three estrogens were nearly equipotent. These data are consistent with AFP regulation of estrogen potency. On days 10-14, uterine growth was less sensitive than at other ages to all three estrogens, perhaps related to uterine differentiation and/or the high endogenous serum E2 levels reported at this age. However, when we examined another uterine estrogen response, ornithine decarboxylase (ODC) induction at 6 h following estrogen injection, all three hormones were about equipotent in both neonatal and adult animals. This apparently AFP-independent event shows dissociation of ODC induction and uterine growth, which could be due to separate mechanisms for hormone entry to target tissue or subsequent intracellular events.
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PMID:Dissociation of estrogen-induced uterine growth and ornithine decarboxylase activity in the postnatal rat. 244 28

Estradiol and progesterone were given intramuscularly to seventeen and sixteen male rabbits respectively on every other day for six weeks. After six weeks, gallstone formation were found in all of the rabbits. In two of them there were cholesterol stones in main hepatobiliary ducts. According to the data resulting from estimation of trace elements and lipid components of the gallbladder bile and findings of microscopic and ultramicroscopic examination on the gallbladder wall, the authors suggest that the mechanisms of gallstone formation are probably due to: 1. Estrogens promote nucleation of gallstones; 2. Estrogens raise lithogenic index of the bile; 3. Estrogens cause stagnation of the gallbladder bile.
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PMID:[Experimental study on the relation of estrogens to gallstone formation]. 263 3


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