Estrone Values Research Articles

Electrochemical oxidation of estrogens as a method for CYP19A1 (aromatase) electrocatalytic activity determination

In this study we present an original approach for determination of electrocatalytic activity of CYP19A1 (aromatase), immobilized on screen-printed graphite electrodes modified by didodecyldimethylammonium bromide (DDAB). Using square wave voltammetry we have shown that estrone and β-estradiol produced during CYP19A1-dependent electrocatalytic reactions towards androstenedione and testosterone, respectively, can be determined by their direct electrochemical oxidation on the surface of graphite electrode at Eox = 497 ± 14 mV (vs. Ag/AgCl) for estrone and Eox = 483 ± 17 mV (vs. Ag/AgCl) for β-estradiol, respectively. Sensitivity values for estrone and β-estradiol were determined as 0.1 A/M and 0.12 A/M, respectively. Limits of detection (S/N = 3) were calculated as 11 nM and 3.4 nM for estrone and β-estradiol, respectively. We used estrogen electrochemical oxidation for determination of immobilized on screen-printed graphite electrodes CYP19A1 steady-state kinetic parameters (maximal rate of the reaction – Vmax and Michaelis constant – KM) towards androstenedione and testosterone. Furthermore, we evaluated the applicability of the approach for studying of CYP19A1 inhibitors, using exemestane as an example, which is a known mechanism-based aromatase inhibitor and a drug for breast cancer treatment. The maximal inactivation rate constant (kinact) and half-life of inactivation (t1/2) values for exemestane mechanism-based inhibition towards CYP19A1 in the electrochemical system were estimated as 0.038 ± 0.003 min−1 and 18.2 ± 1.4 min, respectively, while the concentration of inhibitor required for half-maximal inactivation (KI) was calculated to be in a range of 0.3–5.7 nM. The parameters correlate to those obtained previously in CYP19A1-dependent reconstituted systems. The approach is promising for CYP19A1 inhibitor screening during drug development for breast cancer treatment.

Abstract P1-13-08: Arthralgia and changes in serum levels of IGF-I, its binding protein and estrogen in breast cancer patients on endocrine agents

Abstract Objective Aromatase inhibitors (AIs) frequently induce or enhance musculoskeletal problems, also known as the AI-induced musculoskeletal syndrome (AIMSS). Underlying mechanisms are unknown, likely multiple and induced by low estrogen levels. We hypothesized a role for the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis (Lintermans et al, Ann of Oncol 2011). Recently, Gallicchio et al. (J Cancer Res Clin Oncol 2013) confirmed our hypothesis. Here we report the effect of tamoxifen and AIs on AIMSS, IGF-I, its binding protein and estrogen levels from a prospective study. Material & Methods In this prospective cohort study postmenopausal women with an early breast cancer scheduled to start adjuvant endocrine therapy with any of the third generation AIs or tamoxifen were included. After providing informed consent, a rheumatologic questionnaire was completed and serum was collected. AI-induced musculoskeletal pain was defined as an increase in joint or muscle pain relative to baseline; AIMSS presence was defined as the presence of ≥ 3 out of five features (arthralgia, myalgia, joint stiffness, tingling, carpal tunnel syndrome). IGF-I levels were determined in batch with an inhouse radio-immunoassay; levels of IGF binding protein 3 (IGFBP-3) with a commercial EASIA from DiaSource. A sensitive liquid chromatography dual mass spectrometry was used for assessment of estradiol (E2) and estrone (E1) values, with a limit of quantification of 1.3 and 1.2 ng/l, respectively. SHBG levels were determined with the Roche Modular E170 analyzer. Re-evaluation was done after 3, 6 and 12 months of therapy. Results 84 patients started on tamoxifen (n = 42) or an AI (n = 42; anastrozole n = 6, letrozole n = 36). In the AI group, 4 patients discontinued due to AIMSS. In the tamoxifen group, 1 patient developed a deep vein thrombolic event and discontinued tamoxifen therapy. In all BMI categories, AI and not tamoxifen decreased E1 and E2 levels below limit of quantification from month 3 onwards. SHBG values dropped on AI while they increased on tamoxifen. AI therapy resulted in elevated IGF-I and IGF-I/IGFBP-3 ratio levels, whereas tamoxifen users had a decrease. AI-induced musculoskeletal symptoms were characterized by a higher increase from baseline in IGF-I levels and IGF-I/IGFBP-3 ratio than AI users without any complaints. Patients experiencing AIMSS showed a significant decrease in IGFBP-3 levels (p = 0.0007) and an increase in IGF-I/IGFBP-3 ratio (p = 0.07) compared to patients without AIMSS. This divergence was most pronounced at 3 months following AI start. Conclusion These findings provide preliminary evidence that AI-induced musculoskeletal symptoms are associated with changes in the GH/IGF-I axis. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-13-08.

Determination of Selected Endocrine Disrupter Compounds at Trace Levels in Sewage Sludge Samples

Simultaneous determination of endocrine disrupter compounds (EDCs), namely diltiazem, progesterone, benzylbutylphthalate (BBP), estrone, and carbamazepine (Cbz) were performed by using high performance LC–electrospray tandem MS. The ultrasound-aided sequential extraction of sludge samples was optimized to increase extraction efficiencies of the analytes; ranging between 93.0–98.3% recovery. The limit of detection values for diltiazem, progesterone, BBP, estrone, and Cbz were found as 0.78, 0.72, 0.24, 0.75, and 0.72 µg/kg, respectively. Sludge samples taken from Ankara Tatlar; Hurma, Lara and Kemer of Antalya, and Middle East Technical University-vacuum rotating membrane wastewater treatment plant (WWTP) aeration tanks were analyzed for their EDCs contents under optimized conditions. Diltiazem was found in all the samples in the range between 116.4–180.8 ng/g while progesterone and estrone were not detected in any of the samples analyzed with the exception of Tatlar WWTP. The BBP concentration was between beyond detection and 9195.5 ng/g. In addition, Cbz was found in all the samples ranging from 25.6 to 118.8 ng/g.

Single-label time-resolved luminescence assay for estrogen receptor–ligand binding

Homogeneous luminescence-based microplate assays are desirable in high-throughput screening of new nuclear receptor regulators. Time-resolved fluorescence resonance energy transfer (TR–FRET) assays provide high sensitivity due to low background signal. The TR–FRET concept requires labeling of both ligand and receptor, making the assay format and its development relatively expensive and complex compared with single-label methods. To overcome the limitations of the multilabel methods, we have developed a single-label method for estrogen receptor (ER)–ligand binding based on quenching resonance energy transfer (QRET), where estradiol labeled with luminescent europium(III) chelate (Eu–E 2) is quenched using soluble quencher molecules. The luminescence signal of Eu–E 2 on binding to full-length ER is protected from quenching while increasing competitor concentrations displace Eu–E 2 from the receptor, reducing the signal. The QRET method was paralleled with a commercial fluorescence polarization (FP) assay. The measured signal-to-background (S/B) values for estradiol, estrone, fulvestrant, and tamoxifen obtained for the QRET assay (5.8–9.2) were clearly higher than the S/B values for the FP assay (1.3–1.5). A K d value of 30 nM was calculated for binding of Eu–E 2 to ER from a saturation binding isotherm. The QRET method provides an attractive new single-label assay format for nuclear receptor ligand screening.

Plasma estrogen concentrations after oral and vaginal estrogen administration in women with atrophic vaginitis

In this open-label, randomized, multiple-dose, two-treatment crossover study, 24 postmenopausal women with moderate to severe atrophic vaginitis received 0.3 mg conjugated estrogens daily for 14 days: 7 days orally (0.3 mg tablet) and 7 days vaginally (0.5 g cream). Steady-state plasma concentrations of E2 and estrone were one-third lower after vaginal versus oral administration of conjugated estrogens.

Serum Sclerostin Levels Negatively Correlate with Parathyroid Hormone Levels and Free Estrogen Index in Postmenopausal Women

Sclerostin is a negative regulator of bone formation. The aim of the study was to compare serum sclerostin levels in premenopausal and postmenopausal women and evaluate its relationship to estrogen, TH, bone turnover, and bone mass. We conducted a cross-sectional observational study of healthy community-dwelling pre- and postmenopausal women. There were no interventions. We compared serum sclerostin levels in pre- and postmenopausal women and correlated sclerostin levels with female sex hormones, calciotropic hormones, bone turnover markers, and bone mineral density. Premenopausal women were 26.8 yr old, and postmenopausal women were 56.8 yr old. Postmenopausal women had lower values for estradiol (30 +/- 23 vs. 10 +/- 4 pg/ml; P < 0.001), estrone (61 +/- 24 vs. 29 +/- 10 pg/ml; P <0.001), and free estrogen index (FEI) (6 +/- 4 vs. 3 +/- 2 pmol/nmol; P = 0.008) and significantly lower bone mineral density at all sites compared to premenopausal women, with no significant differences in levels of PTH, 25-hydroxy or 1,25-dihydroxy vitamin D levels. Postmenopausal women had significantly higher serum sclerostin levels (1.16 +/- 0.38 ng/ml vs. 0.48 +/- 0.15 ng/ml; P < 0.001). Because most of the premenopausal women were on oral contraceptives, subsequent analyses were limited to postmenopausal women. There were significant negative correlations between sclerostin and FEI and sclerostin and PTH in this group. Using multiple regression analysis, both FEI (beta = -0.629; P = 0.002) and PTH (beta = -0.554; P = 0.004) were found to be independent predictors of sclerostin levels in postmenopausal women. Our findings suggest that serum sclerostin levels are regulated by both estrogens and PTH in postmenopausal women. These findings need to be explored further in larger prospective studies.

Sorption of Selected Endocrine Disrupting Chemicals to Different Aquatic Colloids

The sorption of seven endocrine disrupting chemicals (EDCs) to aquatic colloids was determined by cross-flow ultrafiltration (CFUF) followed by gas chromatography-mass spectrometry (GC-MS). Results show that the colloidal organic carbon normalized sorption coefficient (Kcoc) of EDCs to different aquatic colloids varies by a factor of 6-12 because such colloids are of different origin. Through characterization of colloidal samples, a significant relationship was established between Kcoc values and the molar extinction coefficient of colloids at 280 nm, whereas no other colloidal properties such as elemental ratios were correlated with Kcoc values. The results are consistent with other reports of the importance of the quality of sorbents such as their aromatic carbon content in sorbing various organic pollutants. The presence of a surfactant was found to increase Kcoc values for estrone (El) and 17alpha-ethynylestradiol (EE2). The method was subsequently applied for determining EDC concentrations in field samples, where both conventional and truly dissolved EDCs showed higher concentrations close to sewage outfalls than either upstream or downstream, confirming the sourceconcentration relationship. In addition, the truly dissolved EDC concentrations were lower than the conventional dissolved concentrations, confirming that there were interactions between aquatic colloids and EDCs. It is estimated that between 10 and 29% of EDCs are associated with aquatic colloids. As colloids are highly abundant in rivers and ocean, they will therefore play a significant role in the environmental behavior and fate of EDCs.

Sorption, Mobility, and Transformation of Estrogenic Hormones in Natural Soil

Potent estrogenic hormones are consistently detected in the environment at low concentration, yet these chemicals are strongly sorbed to soil and are labile. The objective of this research was to improve the understanding of the processes of sorption, mobility, and transformation for estrogens in natural soils, and their interaction. Equilibrium and kinetic batch sorption experiments, and a long-term column study were used to study the fate and transport of 17beta-estradiol and its primary metabolite, estrone, in natural soil. Kinetic and equilibrium batch experiments were done using radiolabeled 17beta-estradiol and estrone. At the concentrations used, it appeared that equilibrium sorption for both estrogens was achieved between 5 and 24 h, and that the equilibrium sorption isotherms were linear. The log K(oc) values for 17beta-estradiol (2.94) and estrone (2.99) were consistent with previously reported values. Additionally, it was found that there was rate-limited sorption for both 17beta-estradiol (0.178 h(-1)) and estrone (0.210 h(-1)). An approximately 42 h long, steady-flow, saturated column experiment was used to study the transport of radiolabeled 17beta-estradiol, which was applied in a 5.00 mg L(-1) solution pulse for 44 pore volumes. 17beta-estradiol and estrone were the predominant compounds detected in the effluent. The effluent breakthrough curves were asymmetric and the transport modeling indicated that sorption was rate-limited. Sorption rates and distributions of the estrogens were in agreement between column and batch experiments. This research can provide a better link between the laboratory results and observations in the natural environment.

Relationship between estradiol 16α-hydroxylation and human papillomavirus infection in cervical cell transformation

The ovarian steroid hormone estradiol and its metabolite estrone were examined in 45 normal women and 127 premenopausal women with precancerous cervical lesions. Interviews ,colposcopy and cervical scrapingswere performed. The mean ± SD values for estradiol and estrone were 0.07 ± 0.08 ng/ml and 0.06 ± 0.02 ng/ml ,respectively in normal subjects. Corresponding data in patients with cervicalintraepithelial neoplasia alone or in association with human papillomavirus (HPV) infection were 0.074 ± 0.03 ng/ml and 0.076 ± 0.03 ng/ml or 0.080 ± 0.03 ng/ml and 0.148 ± 0.02ng/ml ,respectively ,which revealed a significantly greater extent of estrogenic action in the latter population (p < 0.05). We considered that the presence of HPV infection probably increased16α-hydroxylation of estradiol ,providing a possible link between the viral and hormonal elements ,possibly having a bearing on the etiology of the disease.

The menopausal transition: a dynamic approach to the pathogenesis of neurovegetative complaints

In our cross-sectional study we investigated the separate influence of three main factors, namely menopausal and estrogen status, and chronological age, on ten neurovegetative climacteric complaints reported in the scale of Kupperman et al. A multivariate statistical analysis was performed by a multivariate statistical approach on 1161 untreated women seen at the Menopause Center of the Ferrara University Hospital. Ninety women (age range, 41–54 years) were premenopausal; 492 women (age range, 38–55 years) were perimenopausal with irregular periods or amenorrhea for less than 12 months; 468 women (age range, 41–69 years) had a spontaneous menopause (age range, 37–66 years); 111 had had hysterectomy with bilateral ovariectomy while still regularly menstruating. Serum estrone was used as the indicator of the patients' estrogen status. A clear positive trend was demonstrated between menopausal status and the prevalence of depression, hot flushes, insomnia and joint pain. However, only the prevalence of hot flushes amongst these four symptoms was significantly related with the climacteric estrogen decline (β = −0.006, P = 0.001). Moreover, menopausal status appeared to influence the intensity of fatigue, hot flushes, insomnia and paresthesia. Age was found to significantly ( P = 0.053) co-vary only with the intensity of the hot flushes, with a positive relation (β = 0.092, r = 0.104, P = 0.003), whereas estrone values did not significantly co-vary with any symptom. Furthermore, while neurovegetative symptoms are largely present also in the absence of hot flushes, when these latter are present, they exacerbate both the intensity and the prevalence of all the other symptoms. We conclude that hot flushes seem to act on all of the other neurovegetative symptoms in two fashions. First, they elicit complaints already sub-clinically present; second, they worsen neurovegetative complaints clinically present. Menopausal status, on the other hand, appears to significantly influence both the prevalence and the intensity of hot flushes, whereas estrogen decline significantly influences the prevalence but not the intensity of this symptom, which appears to be related only to age.

Characterization of guinea pig estrogen sulfotransferase expressed by Chinese hamster ovary cell-K1 stable transfectants.

Estrogen sulfotransferase (EST) activity expressed by Chinese hamster ovary (CHO)-K1 cells stably transfected with a plasmid containing a guinea pig EST complementary DNA insert was subjected to biochemical characterization, and the EST protein was further examined by nondenaturing isoelectric focusing and immunoblot analysis. CHO-K1 cells transfected with the same plasmid without the EST complementary DNA insert as well as untransfected CHO-K1 cells did not demonstrate either EST activity or the presence of an immunologically related protein. The EST expressed by the stably transfected CHO-K1 cells was found to manifest Michaelis-Menten kinetics and would use only estrogenic steroids as substrates, whereas other forms of steroids, such as pregnenolone, dehydroepiandrosterone, cortisol, and testosterone, were not acted on. When 17 beta-estradiol was used as a substrate, sulfonation occurred exclusively at the 3 position; 17-sulfonate was not formed. Thus, the expressed EST acted selectively on the 3-hydroxyl group of phenolic steroids. The apparent Km values for estrone, 17 beta-estradiol, and estriol were 60, 70, and 40 nM, respectively. The maximum velocity (Vmax) determinations for estrone and 17 beta-estradiol were equivalent, whereas the Vmax for estriol was reduced by 33%. Of the three estrogens, only 17 beta-estradiol caused substrate inhibition at a high concentration. Steroid sulfonation requires 3'-phosphoadenosine-5'-phosphosulfate (PAPS) as the active sulfonate donor, and the Km value for PAPS was 1.2 microM. In steroid sulfotransferase reactions, two products are formed: the sulfonated steroid product and the desulfonated cofactor, 3'-phosphoadenosine-5'-phosphate (PAP). The sulfonation of 17 beta-estradiol was inhibited by PAP in a dose-dependent manner. In addition, the Km for PAPS was increased by PAP, whereas the Vmax was unaffected, indicating competitive inhibition (Ki, approximately 0.52 microM). The EST protein expressed by the CHO-K1 cell stable transfectants demonstrated a mol wt of 34 kilodaltons, as determined by sodium dodecyl sulfate-gel electrophoresis. Additionally, when the expressed EST protein was subjected to isoelectric focusing, it was found to consist of multiple charge isoforms. These findings are comparable to what has been previously reported for native guinea pig adrenocortical EST. Furthermore, the charge isoform pattern that was demonstrated for the expressed EST was similar to the pattern observed for the native protein.

Changes in 17β,20α-hydroxysteroid dehydrogenase activity supporting an increase in the estrogen/progesterone ratio of human fetal membranes at parturition

Our purpose was to measure the activity of the reversible enzyme 17 beta,20 alpha-hydroxysteroid dehydrogenase around parturition with estrogen and progestogen substrates. Classic kinetic studies and explant cultures were used to determine kinetic parameters and net enzyme activities in both oxidative and reductive directions for both sets of substrates. Affinity constant values for estrone, estradiol, and 20 alpha-dihydroprogesterone were 1 to 8 mumol/L. Affinity constant for progesterone was 9 to 25 mumol/L. Maximal velocities for all substrates in the chorion were 20- to 70-fold higher than in amnion and severalfold higher for estrogen substrates compared with the progestins. Around parturition there was a significant change toward net formation of the stronger estrogen (estradiol) and the weaker progestin (20 alpha-dihydroprogesterone), suggesting an increase in the local estrogen/progesterone ratio. The enzyme 17 beta,20 alpha-hydroxysteroid dehydrogenase may be an important regulator of the local estrogen/progesterone ratio in fetal membranes around the time of parturition.

Follicle-stimulating hormone plays a role in the induction of ovarian follicular cysts in hypophysectomized rats.

Unabated stimulation by low doses of LH-like activity produces ovarian follicular cysts in both progesterone-synchronized immature rats and pregnant rats. Serum FSH is maintained in both of these models at values similar to those observed on diestrus. To determine whether unabated stimulation by basal serum FSH affects the ability of LH-like activity to induce cystic ovaries, immature hypophysectomized (HYPOXD) rats were given either no hormone (control); 2 micrograms ovine FSH (oFSH) once daily for 14 days beginning on Day 27; 0.5 IU hCG twice daily for 13 days beginning on Day 28 of age; or both oFSH and hCG (FSH + hCG) beginning on Day 27 and Day 28, respectively. By the end of the in vivo treatments (Day 40 of age), the largest follicles in the ovaries of control and hCG-treated HYPOXD rats were at the preantral stage of development, whereas the largest follicles present in ovaries from FSH-treated animals were atretic and at the small antral stage of development. In contrast, ovaries from rats treated with FSH + hCG displayed large follicular cysts by Day 37 of age. Of the serum steroids analyzed, only estradiol and androstenedione concentrations for animals treated with FSH + hCG were consistently elevated above values observed for control HYPOXD rats. Serum testosterone and dihydrotestosterone values were similar for hCG-treated and control HYPOXD rats throughout the in vivo treatments. In contrast, these steroids were elevated between Days 3 and 5 of FSH treatment (+/- hCG treatment). Serum progesterone and estrone values for all in vivo gonadotropin treatment groups were similar to those of controls. Serum insulin concentrations were not affected by any in vivo treatment. Incubates of follicles/cysts from FSH + hCG-treated HYPOXD rats contained more progesterone, androstenedione, and estradiol than incubates of follicles from any other in vivo treatment group. Follicles from all in vivo treatment groups responded to 8-bromo cAMP (cAMP) with increased in vitro progesterone accumulation. However, only follicles from FSH-treated and FSH + hCG-treated rats responded to cAMP with increased androstenedione and estradiol accumulation in vitro. Inclusion of 400 ng of either androstenedione or testosterone in the incubation medium enhanced progesterone accumulation in follicular incubates from control, hCG-treated, and FSH-treated HYPOXD rats, but did not enhance progesterone accumulation in follicular incubates from FSH + hCG-treated animals. Both androstenedione and estradiol production increased markedly under these conditions for follicles from all in vivo treatment groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Steroid concentrations in follicular fluid of sows treated with dexamethasone

The effect of injecting the glucocorticoid, dexamethasone (DXM), on ovarian follicular development and steroid concentrations in the sow was investigated. Control sows were injected with 1 ml physiological saline solution i.m. and treated sows were injected with 30 μg kg −1 bodyweight DXM i.m.; both treatments were administered every 12 h from Days 9 to 14 of the estrous cycle. Two experiments were conducted. In Experiment one, follicular fluid was collected and pooled from sows under sodium pentobarbital anesthesia on Days 5, 8, 12, 15, 17 and 19 for control animals and on Days 12, 15, 17, 19 and 26 (Day 5 of next cycle) for DXM-treated animals. Sows given DXM subsequently exhibited poorly defined signs of estrus. On Day 26 their ovaries possessed numerous small cyst-like follicles but few corpora lutea compared to control ovaries that contained corpora lutea and newly developing follicles on Day 5. Androstenedione and estradiol concentrations were lower ( P < 0.05) in follicular fluid from DXM-treated sows on Day 12. Progesterone concentrations varied through the cycle but, like testosterone and estrone values, did not differ significantly between treatments. In Experiment two, concentrations of steroid hormones were examined in individual follicles from the two treatment groups on Day 14 and on Day 19. On these two days, similar numbers of follicles less than 5 mm diameter were present in the two groups but only one third to one half of follicles more than S mm diameter were seen in DXM-treated sows. On Day 14 concentrations of androstenedione, testosterone and estradiol were lower ( P < 0.01) in all follicular size groups from sows receiving DXM. At Day 19 differences in steroid concentrations were not detected in follicles less than S mm diameter. In larger follicles from sows that had received DXM earlier in the cycle, however, the concentrations of the two androgcns and of the two estrogens were less ( P < 0.01) than those present in control sows. The results suggest that a limitation in the amount of androstenedione available as precursor may contribute to the low estradiol concentrations present in follicular fluid while sows are receiving DXM. As a consequence of this treatment follicles attaining a diameter greater than 5 mm may be limited in their steroidogenic capacity during the follicular phase of the cycle.

Dietary calcium and bone mineral density in men

We have observed that familial factors have a decided influence on the plasma content of sex steroids in men both in the general population and in men of families with prostatic cancer. The contribution of genetic and nongenetic familial factors on the variation of plasma sex steroid content and action has now been investigated in 75 pairs of normal male monozygotic (MZ) twins and 88 pairs of dizygotic (DZ) twins. Zygosity was determined by measuring ten blood proteins and enzymes. The mean plasma values for testosterone (T), dihydrotestosterone (DHT), estradiol (E2), estrone (E1), and 3α-androstanediol glucuronide (3α-diol G), free T, LH, FSH, SHBG, age, and degree of adiposity were all similar between the groups of twins. Familial factors (P < 0.01) accounted for 50% or more of the variation in plasma hormone levels in MZ twins (3α-diol G, 84%; TDHT, 70%; T, 63%; E1, 63%; free T, 61%; E2, 57%; DHT, 56%; LH, 55%; and FSH, 54%) except for SHBG, which was 30%. The familial influence was greater in MZ twins than in DZ twins for all measurements except for SHBG. The heritability of the variation of hormone levels in plasma was determined from the equation: 2[rMZ(intraclass correlation) - rDZ]. Genes regulate 25% to 76% of the total variation of plasma content of the hormones except for DHT (12%) and SHBG (<1%). Genetic regulation of tissue DHT formation was suggested by observing a 48% genetic effect on the plasma content of 3α-diol G. These observations suggest that genetic factors make major contributions in regulating estrogen and testosterone levels and tissue DHT production in normal men.

Menstrual cycle characterization and artificial insemination in the black mangabey (Cercocebus aterrimus)

AbstractConcentrations of immunoreactive estrone conjugates, pregnanediol‐3‐glucuronide, and luteinizing hormone were measured and indexed to creatinine in daily urine samples from three female black mangabeys (Cercocebus aterrimus). Daily observations of menstruation and perineal tumescence were recorded. The mean ± SEM lengths of the menstrual cycle [apparent cycle length of 26.0 ± 0.8 days determined by observation of intermenstrual intervals (n = 26); physiologic cycle length of 31.3 ± 5 days determined by urinary endocrine analysis (n = 4)], follicular phase [16.5 ± 4 days (n = 4)], and luteal phase [14.8 ± 1 day (n = 4)] were determined. The apparent cycle length is probably more accurate.Perineal tumescence began during or shortly after menstruation, increased concomitantly with increasing follicular phase conjugated estrone values, and reached maximal size in the periovulatory period. Ovulation was closely followed by a drop in conjugated estrone levels, an increase in urinary pregnanediol‐3‐glucuronide, and perineal detumescence. Peak concentrations of conjugated estrone and luteinizing hormone values were coincident. Pregnanediol‐3‐glucuronide accurately reflected luteal function in the black mangabey.Knowledge of the menstrual cycle parameters and their correlation to perineal tumescence was used to time artificial inseminations. Semen was obtained by rectal electroejaculation. Coagulum and extended semen, or trypsin‐digested coagulum, were used for insemination. One insemination of trypsin‐digested coagulum at the external os of the cervix resulted in a probable conception, follówed by apparent abortion after 3 weeks.

Estrogen dynamics in the female rhesus monkey.

The metabolic clearance rates (MCR) and interconversions [( rho]BB) values for estrone (E1) and estradiol (E2) in female rhesus (Macaca mulatta) monkeys on Days 9, 14, and 23 of the menstrual cycle were measured using constant infusions of [3H] estradiol and [14C] estrone. The menstrual cycles in these monkeys were reproduced by using Silastic capsules of E2 and progesterone after bilateral ovariectomy. The serum levels of E2 and progesterone were measured by radioimmunoassay and were similar to those for the intact menstrual cycle. The MCR of E2 on Day 14 (52.8 +/- 6.8 l/day/kg) was significantly greater (p less than 0.05) than that measured on Day 9 (31.1 +/- 3.6 l/day/kg) or Day 23 (35.4 +/- 2.1 l/day/kg). The MCR of E1 was also different (p less than 0.05) on Day 14 (77.6 +/- 14.9 l/day/kg) compared to the values on Days 9 and 23 (50.2 +/- 4.9 and 48.2 +/- 3.9 l/day/kg, respectively. There was no change in percentage of free E2, percentage of albumin-bound E2, or sex hormone-binding globulin levels on those 3 days of the cycle. The interconversions between E2 and E1 were not influenced by the day of the cycle. We conclude that the high levels of E2 occurring at the time of the E2 peak result in increases in the MCRs of both E2 and E1 that are not associated with changes in the pattern of protein-binding or in the activity of the 17 beta-hydroxy steroid dehydrogenase.

Urinary steroid concentrations during natural and gonadotrophin-induced oestrus and pregnancy in the giant panda (Ailuropoda melanoleuca).

Urinary concentrations of conjugated oestrone and pregnanediol-3-glucuronide were measured during and after spontaneous and induced oestrus and during pregnancy. Behavioural oestrus was preceded by a rise in oestrone values from less than 10 ng/mg creatinine (Cr) to peaks of 45 ng/mg Cr. Maximal lordotic response and mating activity coincided with the decline in oestrone levels. After presumed ovulation, urinary pregnanediol glucuronide concentrations increased from less than 5 to 15-30 ng/mg Cr. Further increases in this steroid (to 60-80 ng/mg Cr) occurred 114 days after mating, presumably coincident with implantation. These high levels of pregnanediol glucuronide were maintained for 3 weeks, began to decline 1 week before parturition and fell to a nadir (less than 5 ng/mg Cr) immediately after delivery. When FSH was administered i.m. for 5 days, urinary oestrone values rose markedly and were maximal (580 ng/mg Cr) on Day 7. Mating first occurred on Day 20 and 500 i.u. hCG were given i.m. Urinary pregnanediol glucuronide levels during the next 5 months were similar to those in the previous year during pregnancy with values rising 105-108 days after mating. However, no birth occurred. These results support the suggestion that pandas exhibit delayed implantation and demonstrate that the panda is responsive to exogenous gonadotrophins.

Sex hormones in obese premenopausal women and their relationships to body fat mass and distribution, B cell function and diet composition.

We examined sex hormone blood concentrations in a group of 33 obese non-hirsute premenopausal women with normal menses and in 14 age-matched normal-weight controls, and evaluated their relationship with anthropometric parameters, dietary habits and insulin levels. Obese women showed lower than control sex hormone-binding globulin (24.9 +/- 14.6 vs 38.6 +/- 12.5 nmol/l; p less than 0.005) and 5 alpha-dihydrotestosterone (13.7 +/- 5.4 vs 18.2 +/- 4.8 ng/dl; p less than 0.005) values. Despite their consensual behavior, the correlation coefficient between 5 alpha-dihydrotestosterone and sex hormone-binding globulin was not significant in the obese while in controls it was 0.68 (p less than 0.01). This suggests that mechanisms operating to lower the plasma levels of these compounds may be regulated differently in obesity. Body Mass Index, per cent body fat and its distribution showed a highly significant negative correlation with sex-hormone binding-globulin and 5 alpha-dihydrotestosterone values. Insulin levels did not appear to be correlated with sex hormone values. On the contrary, in the obese women we found a highly significant correlation between dietary lipids and sex-hormone-binding-globulin levels (r = -0.54; p less than 0.005) and between dietary carbohydrates and estrone values (r = 0.47; p less than 0.005); all these relationships were independent of body weight. These results confirm that in premenopausal women obesity may be characterized by detectable changes in sex steroid metabolism and suggest a possible causal role not only of the excessive quantity of metabolically active adipose tissue but also of specific dietary factors.

Quantitating genetic and nongenetic factors that determine plasma sex steroid variation in normal male twins

We have observed that familial factors have a decided influence on the plasma content of sex steroids in men both in the general population and in men of families with prostatic cancer. The contribution of genetic and nongenetic familial factors on the variation of plasma sex steroid content and action has now been investigated in 75 pairs of normal male monozygotic (MZ) twins and 88 pairs of dizygotic (DZ) twins. Zygosity was determined by measuring ten blood proteins and enzymes. The mean plasma values for testosterone (T), dihydrotestosterone (DHT), estradiol (E 2), estrone (E 1), and 3α-androstanediol glucuronide (3α-diol G), free T, LH, FSH, SHBG, age, and degree of adiposity were all similar between the groups of twins. Familial factors ( P < 0.01) accounted for 50% or more of the variation in plasma hormone levels in MZ twins (3α-diol G, 84%; T DHT , 70%; T, 63%; E 1, 63%; free T, 61%; E 2, 57%; DHT, 56%; LH, 55%; and FSH, 54%) except for SHBG, which was 30%. The familial influence was greater in MZ twins than in DZ twins for all measurements except for SHBG. The heritability of the variation of hormone levels in plasma was determined from the equation: 2[r MZ(intraclass correlation) - r DZ]. Genes regulate 25% to 76% of the total variation of plasma content of the hormones except for DHT (12%) and SHBG (<1%). Genetic regulation of tissue DHT formation was suggested by observing a 48% genetic effect on the plasma content of 3α-diol G. These observations suggest that genetic factors make major contributions in regulating estrogen and testosterone levels and tissue DHT production in normal men.