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Pharmacokinetics of a 7-day 17 beta-estradiol transdermal delivery system: effect of application site and repeated applications on serum concentrations of estradiol and estrone.

FemPatch (Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, Ann Arbor, MI), a new 7-day 17 beta-estradiol transdermal delivery system (TDS), has been developed for treatment of menopausal vasomotor symptoms. This two-period crossover study was conducted to determine the effects of TDS application site (buttocks versus abdomen) and early TDS replacement on estradiol and estrone concentrations, and to quantify intersubject and intrasubject pharmacokinetic variability. Eighteen healthy, postmenopausal female volunteers received a single 7-day TDS application to the abdomen and repeated TDS applications to the buttocks (regular replacement on days 7 and 14, intentional early replacement on day 17, and removal on day 21). Serial serum samples were assayed for estradiol and estrone by validated radioimmunoassay methods. The 7-day TDS delivers estradiol at a constant, near zero-order rate for the duration of application, independent of application site. Mean serum estradiol concentrations were higher after application to the buttocks than after application to the abdomen (19 and 15 pg/mL above baseline, respectively), making the buttocks the preferred site for TDS application. Mean serum concentration of estradiol was slightly higher (23 pg/mL above baseline) for the treatment week with early TDS replacement due to the transient increase in concentration over the first 24 hours after replacement. Parallel but smaller increases in concentrations of estrone were observed. Serum estradiol and estrone concentrations are reproducible within an individual from application to application (coefficient of variation, 25%). Variability between individuals was higher (coefficient of variation, 40-50%).

Abdomen↗

Assignment of estradiol-17 beta dehydrogenase and of estrone reductase to cytoplasmic structures of porcine endometrium cells.

Homogenates of porcine endometrium contain substantial activity for the dehydrogenation of estradiol-17 beta but little for estrone reduction. Both activities are associated with cytoplasmic structures. The dehydrogenase is characterized by a pH 7.7 optimum, Km 2.2 x 10(-7) mol/l for estradiol and Km 4.4 x 10(-5) mol/l for the cosubstrate NAD+. The corresponding figures for the reductase are pH 6.6, Km 1.1 x 10(-6) mol/l for estrone and Km 2.1 x 10(-5) mol/l for the cosubstrate NADPH. The (mitochondrial/lysosomal) 17,000 x g particulate fraction contains a 52-fold higher dehydrogenase than reductase activity. The (microsomal) 200,000 x g particulate fraction is only 16-fold richer in dehydrogenase. Isopycnic centrifugations of the two fractions in Percoll gradients reveal that estrone reductase and the coequilibrating marker enzyme cytochrome c reductase occur in constant proportions, whereas the dehydrogenase/cytochrome c reductase ratios are different. Both, the kinetic data and the structural assignments speak in favour of individual enzymes catalyzing the dehydrogenation of estradiol and the reduction of estrone. All gradient fractions exhibiting dehydrogenase activity feature small, electrodense vesicles of 0.15-0.20 microns in diameter as a common structural element which might harbour the dehydrogenase.

17-Hydroxysteroid Dehydrogenases↗

Serum levels of total dehydroepiandrosterone and total estrone in postmenopausal women with special regard to carcinoma of the uterine corpus.

Serum levels of total dehydroepiandrosterone and total estrone were determined in 18 postmenopausal women with carcinoma of the uterine corpus (stage I, grade 1-3) and in 40 healthy postmenopausal women. Elevated levels of both steroids were found in the carcinoma group, for dehydroepiandrosterone 2010+/-195 vs. 1299+/-117 nM, p less than 0.01, and for estrone 2,38+/-0.24 vs. 1.36+/-0.11 nM, p less than 0.001. Dehydroepiandrosterone as well as the precursors of estrone are almost exclusively of adrenal origin in the postmenopausal woman. Thus these findings indicate a role of the adrenal cortex in the etiology of corpus carcinoma, either by providing increased levels of substrate for the peripheral synthesis of estrone or a direct action of adrenal androgens on the endometrial tissue.

Aged↗

Metabolism of estrone sulfate in human endometrium.

The metabolism of [3H] estrone sulfate was studied in endometrial tissue obtained from postmenopausal women with atrophic endometrium (I), benign endometrial proliferative changes (II) and endometrial carcinoma (III) and in perimenopausal women with proliferative (IV) and secretory (V) endometrium. Total hydrolysis (i.e. formation of [3H] estrone + [3H] estradiol-17 beta) of [3H] estrone sulfate as well as formation of [3H] estradiol-17 beta only was significantly less in group I than in the other groups. The formation of [3H] estradiol-17 beta was greater in group V than in the other groups. It is speculated that formation of estradiol-17 beta in the endometrium from estrone sulfate may be of importance in the genesis of endometrial disorders in the postmenopausal woman.

Aged↗

Estrone modulates the EGF receptor in the liver of db/db mouse.

The genetically diabetic db/db mouse is an excellent model to study the effect of diabetes on hormone receptors. The decrease of EGF binding sites could be detected in the hepatic microsomes of diabetic mice as early as 3 weeks of age. In addition, there was an age-related decrease in the autophosphorylating activity of EGF receptor isolated from the liver of diabetic mice. Estrone feeding (0.005%) partially restored this autophosphorylating activity. Northern blot analysis showed that the hepatic EGF receptor transcripts were dramatically decreased during the progression of diabetes and could be reversed by estrone feeding. Transfection experiments carried out on HepG2 cells using EGF receptor promoter (pERCAT-6) demonstrated that addition of 2 x 10(-8) M estrone stimulated chloramphenicol acetyltransferase activity. Our results suggest that estrone modulates EGF receptor by enhancing EGF receptor transcripts and the promoter activity of this gene.

Animals↗

[Experimental investigations into the effect of Escherichia coli and Clostridium perfringens on the steroid estrone].

Together with the faecal and the urinary discharge of animals and humans natural and synthetic estrogenes are excreted into the environment. About their degradation in the environment only few facts are known. Their reduction is probably of microbial enzymatical nature. For looking into that question it was investigated by in-vitro-attempts whether Escherichia coli or Clostridium perfringens influence the estrone. Therefore estrone was incubated together with the microorganisms tested (experimental groups) and without those (control groups) in nutrient medium for these bacteria over 48 hours with 37 degrees C (aerobic) or 42 degrees C (anaerobic). For the executed procedure an enzyme immunoassay was used. It could be seen that E. coli does not show a provable effect on the estrone concentration under this conditions. Whereas C. perfringens might have a potency for the degradation of the hormone tested. The experiments shows that there exists obviously a difference between estrone and 4-pregnene-20 beta-o1-3-one in the same system of test.

Animals↗

Acute effect of alcohol on estradiol, estrone, progesterone, prolactin, cortisol, and luteinizing hormone in premenopausal women.

BACKGROUND: Heavy alcohol consumption is associated with menstrual irregularities, including anovulation, luteal-phase dysfunction, recurrent amenorrhea, and early menopause. In addition, moderate to heavy alcohol intake has been found to increase the risk of spontaneous abortions and breast cancer. These adverse effects could at least in part originate from alcohol-mediated changes in hormone levels. METHODS: The acute effect of alcohol on the hormone balance in women using oral contraceptives (OC+) and also in nonusers (OC-), was evaluated in 30 OC- and 31 OC+ subjects, representing the whole period of the menstrual cycle. It was also evaluated in 40 OC- and 47 OC+ subjects during the midcycle phase and in 10 OC+ subjects with unknown cycle phase. RESULTS: We found that among subjects who used oral contraceptives, estradiol levels increased and progesterone levels decreased after intake of alcohol (0.5 g/kg). No dose effect (0.34-1.02 g/kg) on progesterone was observed in a substudy on 10 OC+ subjects. With regard to estrone levels, no effect was observed, although a significant increase was found in the estradiol-to-estrone ratio. Among subjects not using oral contraceptives, progesterone levels decreased after intake of alcohol (0.5 g/kg). No effect was found in estradiol, estrone, or the estradiol-to-estrone ratio during midcycle in this study group. A transient elevating effect of alcohol (0.5 g/kg) on prolactin levels was observed in both study groups. We found that alcohol (0.5 g/kg) had no significant effect on luteinizing hormone (LH) levels among subjects not using oral contraceptives, and observed a decline among subjects using oral contraceptives at midcycle. CONCLUSIONS: We suggest that the estradiol and progesterone effects are related to decreased steroid catabolism, resulting from the alcohol-mediated increase in the hepatic NADH-to-NAD ratio. The transient effect on prolactin levels may reflect acute changes in opioid and dopamine levels in the hypothalamus. The present findings regarding female sex steroids may be of relevance in the association between moderate to heavy alcohol consumption and the development of breast cancer.

Adult↗

[Effects of estrone on transmission at neuromuscular junction of the toad].

The effects of estrone on neuromuscular transmission were studied intracellularly at the muscle fiber endplate in isolated sciatic nerve-sartorius muscle preparations of the toad (Bufo bufo gargarizans) in vitro. The results showed that estrone (10(-4) mol/L), added to bath medium, caused an increase in amplitudes of endplate potentials (EPP) both in 10 micrograms tubocurarine treated and 10 mmol/L MgCl2 treated preparations, but the increase was more prominent in the former, and that estrone, 30 min after being added to bath medium, caused clear increase both in frequency and amplitude of miniature endplate potentials (MEPP), but the wave form of MEPP remained unchanged and the resting membrane potentials were also unchanged. These results suggest that estrone can increase neuromuscular transmission, which seems to involve primarily the presynaptic mechanism.

Animals↗

Dsorption of estrone on nanofiltration and reverse osmosis membranes in water and wastewater treatment.

Adsorption of the trace contaminant estrone, a natural hormone and commonly abundant in surface waters and in treated as well as untreated wastewaters, to eight commercial nanofiltration and reverse osmosis membranes was investigated under well defined conditions. Experiments were conducted in stainless steel stirred cells by spiking trace levels (100 ng x L(-1)) of estrone into five different matrices, namely MilliQ water, a bicarbonate solution, synthetic natural waters containing natural organics, and secondary effluent. Results show that estrone is adsorbed to the membranes to varying degrees with extent of adsorption influenced by the feedwater composition with different mechanisms of association controlling adsorption to different membrane types. Increase in membrane resistance is typically observed to result in decrease in extent of estrone adsorption.

Adsorption↗

Inhibition of estrone sulfate-induced uterine growth by potent nonestrogenic steroidal inhibitors of steroid sulfatase.

The present study describes the biological in vitro and in vivo evaluation of 2-methoxy derivatives of estrogenic inhibitors of steroid sulfatase, namely 3-sulfamoyloxy-17alpha-p-tert-butylbenzyl(or benzyl)-1,3,5 (10)-estratrien-17beta-ols. The addition of the 2-methoxy group conserves the potent inhibitory effect on steroid sulfatase activity (IC(50)s of 0.024 and 0.040 nM) while removing the estrogenic action. Using an ovariectomized mouse model, we show that the first generation of steroid sulfatase inhibitors tested, 3-sulfamoyloxy-17alpha-p-tert-butylbenzyl(or benzyl)estra-1,3,5 (10)-trien-17beta-ols and estrone-3-O-sulfamate, are estrogenic compounds stimulating estrogen-sensitive uterine growth. Interestingly, the 2-methoxy-3-sulfamoyloxy-17alpha-benzylestra-1,3,5 (10)-trien-17beta-ol (7) has no estrogenic activity but efficiently blocks (s.c. and p.o.) uterine growth induced by estrone sulfate, which is converted into estrone and then estradiol by steroid sulfatase and type 1 17beta-hydroxysteroid dehydrogenase, respectively. This report clearly shows that a steroid sulfatase inhibitor can efficiently block estrogen action from the inactive precursor estrone sulfate, in vitro and in vivo.

Animals↗

Effect of estrone sulfate on postmenopausal bone loss.

Estrogen replacement therapy confers many beneficial effects to postmenopausal women, such as slowing the rate of bone loss and decreasing the risk of coronary artery disease. This multicenter, placebo-controlled study evaluated the lowest effective daily dose of estrone sulfate (0.3, 0.625, or 1.25 mg) combined with 1000 mg elemental calcium supplementation for preventing bone loss in the immediate supplementation for preventing bone loss in the immediate postmenopausal period. Spinal bone mineral density was measured using quantitative computed tomography. Compared with baseline, bone mineral density increased significantly (P less than .05) after 12 months of 0.625 mg daily (+ 1.9%) or 1.25 mg daily (+ 2.5%). The difference between the 0.625-mg and 1.25-mg doses was not statistically significant. Estrone sulfate administration (0.625 and 1.25 mg) produced significant changes in various lipid measurements at both the 6- and 12-month observation points. The prevalence rates for adverse events were comparable among the estrone sulfate groups and the placebo group. Estrone sulfate 0.625 mg daily, combined with 1000 mg elemental calcium supplementation, was the minimum effective dosage to prevent loss of spinal bone mineral density in postmenopausal women over a 12-month period.

Bone Density↗

Effect of cyclic estrone sulfate treatment on lipid profiles of postmenopausal women with elevated cholesterol levels.

The effects of two doses of cyclic unopposed estrone sulfate therapy on the lipid profiles of 153 healthy postmenopausal women with baseline total cholesterol levels above 219 mg/dL were compared in a multicenter, double-blind, placebo-controlled study. Patients were assigned randomly to one of three treatment groups: estrone sulfate 0.625 mg (N = 59) or 1.25 mg (N = 43), or placebo (N = 51). The median baseline total cholesterol levels of the three treatment groups were 262, 269, and 262 mg/dL, respectively. Total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), and the HDL/LDL ratio were assessed after 6, 9, and 12 months of treatment. There was a significant monotonic dose-response relationship of estrone sulfate in raising HDL levels, lowering LDL levels, and raising the HDL/LDL ratio at all intervals measured. These results indicate that estrone sulfate is effective in creating a beneficial change in the lipid profile of postmenopausal women with elevated baseline total cholesterol.

Cholesterol, HDL↗

Correlation between plasma estradiol and estrone-3-glucuronide in urine during the monitoring of ovarian induction therapy.

An improved radioimmunoassay was developed to determine estrone-3-glucuronide in daily urine. Resulting levels were compared with those of estradiol in plasma of 10 healthy women and 14 undergoing ovulation induction therapy with human menopausal gonadotropin and human chorionic gonadotropin. A highly significant correlation between plasma estradiol and urinary estrone-3-glucuronide in normal (r = .9209; P less than .01) and stimulated (r = .9229; P less than .01) women was demonstrated. These results proved that the pattern of excretion of estrone-3-glucuronide perfectly reflected the changes in plasmatic estradiol levels when monitoring ovarian induction and that estrone-3-glucuronide determinations can provide clinically useful information in human induction therapy.

Adult↗

Measurement of estrone-3-glucuronide in urine by rapid, homogeneous time-resolved fluoroimmunoassay.

We describe a liquid-phase nonseparation time-resolved fluorescence immunoassay for measuring estrone-3-glucuronide in undiluted urine. The sensitivity, specificity, and accuracy are similar to those for a conventional separation fluoroimmunoassay or radioimmunoassay, but the speed, convenience, precision, reliability, and clinical utility of the new method are more advantageous. The labeled antigen, a fluorescent europium chelate covalently linked to estrone-3-glucuronide, is incubated for 10 min with a limited concentration of polyclonal or monoclonal antibodies to estrone-3-glucuronyl-6-bovine serum albumin and 10 microL of standard or sample (undiluted urine) in microtiter wells. The fluorescence emanating from the antibody-free label, which is proportional to the concentration of estrone-3-glucuronide in the standard or sample, is then measured in a time-resolved fluorometer. The method is useful for monitoring ovarian function in women.

Antibodies, Monoclonal↗

Solid-phase enzymoimmunoassay of estrone in serum.

This rapid solid-phase enzymoimmunoassay for estrone in serum or plasma is done on microtiter plates after the serum is extracted with diethyl ether. No chromatographic or centrifugation steps are involved. The detection limit of the assay is 380 fg per well (28 pmol/L). Intra- and interassay coefficients of variation for the assay of low, medium, and high concentrations of estrone in plasma were respectively 4.4, 9.3; 2.3, 9.1; and 2.0, 6.3 percent. There was a good correlation (correlation coefficient 0.95) between estrone concentrations measured with this assay and with a commercial radioimmunoassay. The analytical procedure is simple, and one person can assay 80 serum samples per working day. We conclude that the assay is very suitable for serum estrone measurements and is more convenient than published radioimmunoassays.

Antibody Specificity↗

[Reliability of pregnancy diagnosis in sows using direct radioimmunoassay of estrone-sulfate].

The pregnancy diagnosis in sows using direct radioimmunoassay of estrone-sulphate in the blood serum without sample extraction is described. It was found that for the pregnancy diagnosis the period between days 22 and 30 of pregnancy can be used since in this period the estrone-sulphate concentrations in all pregnant sows markedly exceeded those of 64 non-pregnant animals. The estrone-sulphate estimation cannot be used for the pregnancy diagnosis before day 22 and between day 30 and 40 because the estrone-sulphate concentrations in most samples collected in these periods were lower than 4 nmol.l-1.

Animals↗

[Effect of ovariectomy on plasma levels of progesterone, free and conjugated estrone in pregnant sheep].

Progesterone, free and conjugated estrone were determined in peripheral plasma from ovariectomized and control pregnant ewes in order to observe the ovary contribution to these hormonal levels. Progesterone levels during pregnancy were lower in the ovariectomized ewes than in control, although the differences were significant only until the 120th day of pregnancy. From the 130th day to the 3rd-5th day prepartum, an increase in the hormone levels was observed in both groups of ewes indicating a placentary contribution. Very similar patterns were followed by the free and conjugated estrone concentrations, their levels not being significantly different in either group. Production of conjugated estrone both preceded and reached higher values than that of free estrone. Both hormones showed an abrupt increase in concentration two days before the parturition, decreasing after that. Parturition mechanisms, foetus viability and the length of pregnancy were not affected by ovariectomy.

Animals↗

Hepatic estrone and estradiol glucuronyltransferase activity in pregnancy. Induction by pretreatment with 3-methylcholanthrene and phenobarbital.

Hepatic microsomal estrone and estradiol glucuronyltransferase activity were examined in nonpregnant female and pregnant rats and rabbits. Pregnancy decreased glucuronyltransferase activity towards both substrates by 30% in rats and rabbits when activity was expressed per mg of microsomal protein. Because of the increased size of the liver in pregnancy in the rat, activity was increased in this species when expressed per whole liver. The size of the liver was not increased in pregnancy in the rabbit, so that activity per whole liver was also decreased in this species. Pretreatment of nonpregnant rats with 3-methylcholanthrene had little effect on estradiol glucuronyltransferase activity and increased estrone glucuronyltransferase activity 35%. Similar pretreatment of pregnant rats, however, increased estradiol glucuronyltransferase activity approximately twofold and estrone glucuronyltransferase activity approximately threefold. Phenobarbital was a much less potent inducer of estrone and estradiol glucuronyltransferase activities but did increase activities to a greater extent in pregnant rats than in nonpregnant female controls.

Animals↗