Effects of pulsed electromagnetic fields on the mRNA expression of CAII and RANK in ovariectomized rats.

The present study was designed to determine the effects of pulsed electromagnetic fields (PEMFs) on the mRNA expression of the carbonic anhydrase II (CAII) and receptor activator of NF-κB (RANK) in ovariectomized rats. A total of 48 SD rats were randomly divided into four groups [Sham, OVX, PEMFs, and E(2) (premarin)], 12 rats in each group. Rats in the Sham group received sham ovariectomy, while rats in OVX, PEMFs, and E(2) groups received ovariectomy. Twelve weeks following the surgery, rats (whole body) in the PEMFs group were exposed to PEMFs for 30 days with 3.8 mT, 8 Hz, and 40 min per day; rats in the E(2) group were administered premarin (0.0625 mg/kg/d; intragastric administration 1-2 ml/100 g). Rats in the Sham and OVX groups housed in the same conditions. At the end of intervention, the level of serum estradiol of rats was measured. The gene expression of CAII and RANK in the left ilium of rats was determined with real-time fluorescent-nested quantitative polymerase chain reaction. Compared with the Sham group, the level of serum estradiol in the ovariectomized group was significantly decreased (P < 0.05); compared with the OVX group, CAIImRNA expression was significantly decreased in the PEMFs group and E group (P < 0.05, 0.01, respectively). Compared with the E group, RANKmRNA expression was significantly higher in the PEMFs group (P < 0.05); although RANKmRNA expression decreased in PEMFs group, no statistically significant difference was found between PEMF group and OVX group (P = 0.82). These data suggest that PEMFs could regulate the expression of CAIImRNA in ovariectomized rats.

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.

Effect of one-week treatment with vaginal estrogen preparations on serum estrogen levels in postmenopausal women.

OBJECTIVE: Approximately 50% of postmenopausal women suffer from vaginal atrophy, and a large proportion of them choose intravaginal estrogen preparations administered for local action to avoid systemic exposure to estrogens and its associated risk of breast and uterine cancer. The primary objective of this study was the evaluation of the systematic bioavailability of estradiol and estrone and the pharmacokinetics of two of the most frequently used intravaginal estrogen preparations, namely Vagifem and Premarin cream. DESIGN: While immunobased assays could not previously provide accurate measurement of serum estrogen concentrations in postmenopausal women, we have used validated mass spectrometry assays to measure the pharmacokinetics of serum estradiol and estrone during the 24 hours following the seventh daily application of 25 microg estradiol (Vagifem) and 1 g (0.625 mg) conjugated estrogens (Premarin) cream in 10 postmenopausal women in each group. RESULTS: Serum estradiol was increased on average by 5.4-fold from 3 to 17 pg/mL during the 24-hour period after daily administration of 25 microg estradiol or 1 g (0.625 mg) conjugated estrogens cream. Serum estrone, conversely, increased 150% with Vagifem and 500% with Premarin cream. CONCLUSIONS: The present data using validated, accurate, and sensitive mass spectrometry assays of estrogens show that the Vagifem pill and Premarin cream, after 1 week of daily treatment, cause an approximately fivefold increase in serum estradiol in postmenopausal women, thus indicating that the effects are unlikely to be limited to the vagina and that systemic actions are expected after application of these intravaginal estrogen preparations.

Steady-state pharmacokinetics of conjugated equine estrogens in healthy, postmenopausal women.

OBJECTIVE: To determine the steady-state exposure of conjugated and unconjugated estrogen components following oral administration of conjugated equine estrogens (2 0.625-mg tablets). STUDY DESIGN: A prospective, open-label, single-treatment study conducted at 1 clinical site with 12 healthy, postmenopausal women. Each subject received 7 daily doses of 2 conjugated equine estrogen (0.625-mg) tablets, and blood samples were taken on the last day of dosing for pharmacokinetic analysis of estrogen components. RESULTS: The major estrogen components after estrogen dosing (as determined by steady-state plasma concentration-time curves) were estrone (100 ng x h/mL), equilin (43.1 ng x h/mL) and delta8,9-dehydroestrone (13.6 ng x h/mL). Several 17beta-reduced forms of estrogen also had consistent plasma concentrations during a steady-state dosing interval. Mean t(max) values ranged from 6.2 to 9.0 hours after dosing, and the 24-hour profiles of the various plasma estrogen concentrations at steady state showed limited fluctuations. CONCLUSION: Oral dosing of conjugated equine estrogen at steady state resulted in consistent concentrations of estrogen components during a dosing interval.

Two estrogen replacement therapies differentially regulate expression of estrogen receptors alpha and beta in the hippocampus and cortex of ovariectomized rat.

As estrogens have been implicated in altered cognitive function associated with menopause, the purpose of the present study was to determine the regulatory effects of different estrogen preparations on the expression of estrogen receptor subtypes in the hippocampus and cortex of ovariectomized rats. The expression of estrogen receptor mRNA and protein was determined with RT-PCR and immunohistochemistry, respectively. Two estrogen reagents, Premarin and Progynova, were used in the present study. Premarin, a conjugated equine estrogen, down-regulated ER alpha expression in the hippocampus and cortex of ovariectomized rats and had no effect on levels of ER beta expression in the same two regions. However, Progynova (valerate estradiol) was shown to up-regulate ER beta expression in the hippocampus and cortex and had no effect on the levels of ER alpha expression. Our present data suggest that different estrogen reagents used in estrogen replacement therapy could have different regulatory effects on the expression of estrogen receptor subtypes, which might, at least in part, explain why clinically, different estrogen preparations have distinct estrogenic effects on target organs.

Differential role of K(ATP) channels activated by conjugated estrogens in the regulation of myocardial and coronary protective effects.

BACKGROUND: We have demonstrated that estrogen can reduce myocardial injury in ischemia-reperfusion via activation of ATP-sensitive potassium (K(ATP)) channels. We sought to determine whether the protective effect of estrogen extends to epicardial coronary artery with attenuated vasoconstriction in patients after angioplasty by activation of such channels. METHODS AND RESULTS: The study was designed to prospectively investigate 41 consecutive patients scheduled for elective coronary angioplasty. Pretreatment with estrogen limited myocardial ischemia during coronary occlusion and attenuated postangioplasty coronary vasoconstriction at the dilated and distal segments. An inhibitor of K(ATP) channels, glibenclamide, did not affect coronary vasomotor response, although it abolished the beneficial effect of estrogen on myocardial ischemia. Patients to whom estrogen was administered after the second balloon deflation experienced a similar magnitude of myocardial ischemia as controls but showed significantly attenuated vasoconstriction compared with controls (P=0.0001). Endothelin-1 levels from the great cardiac vein rose significantly from 1.9+/-0.4 to 3.1+/-0.6 pg/mL (P=0.001) 15 minutes after angioplasty in the control group; this was attenuated after estrogen was administered. Significant correlation was found between the changes in coronary vasomotion of the dilated segment and endothelin-1 levels (r=0.65, P<0.0001). CONCLUSIONS: These results demonstrate that estrogen is protective against both myocardial ischemia and coronary vasoconstriction through different mechanisms. The myocardial effect of estrogen was abolished by glibenclamide, which suggests that the cardioprotective effect of estrogen may result from activation of K(ATP) channels. In contrast, estrogen-induced attenuated vasoconstriction is associated with an attenuated release of endothelin-1, independent of K(ATP) activation.

Sex steroids in serum of prepubertal male and female horses and correlation with bone characteristics.

We used radioimmunoassay (RIA) to measure monthly serum levels of unconjugated and conjugated sex steroids (testosterone T, androstenedione A, estradiol E(2), and estrone E(1)) in 4 male and 4 female foals during their first year of life. Maximal production of sex steroids was detected from April to August with hormonal peaks, corresponding to the natural breeding season in adults. In males, only A levels were more steady. Total estrogens (unconjugated plus conjugated E(2) and E(1)) were the major steroids in immature males in contrast to adults. Estrogens generally peaked in young females before males; the major estrogen was E(1), and total estrogens overtook total androgens (unconjugated and conjugated T and unconjugated A). We also sampled 3 male and 3 female foals with bone alterations in adulthood. For all animals, serum levels of four bone formation markers were obtained: osteocalcin (O), hydroxyproline (HP), and alkaline phosphatase (AP), and a radiographic score was determined. Only male foals with normal skeletal frame (good radiographic score GRS) in adulthood showed a correlation (P < 0.01) between the distribution frequency of each bone formation marker and unconjugated E(2) or E(1) levels; this finding highlighted the role of unconjugated estrogens in bone maturation in horses, since this was not found in the groups with bone alterations. In females, the threshold of estrogen synthesis and sensitivity was probably sufficient to be a nonlimiting factor at this stage of development. Our results strongly suggest a differential regulation of the estrogen/androgen balance in horses according to sex, sexual maturation, and photoperiod. Moreover, estrogens appear to be crucial for skeletal development in male colts, and these steroids are good modulators of skeletal frame characteristics in adulthood.

Evaluation of single- and multiple-dose pharmacokinetics of synthetic conjugated estrogens, A (Cenestin) tablets: a slow-release estrogen replacement product.

A multiple-dose, placebo-controlled, randomized pharmacokinetic study was performed in 15 early (i.e., 1-3 years) postmenopausal women to evaluate the single and steady-state pharmacokinetics of 0.625 mg Cenestin (Synthetic Conjugated Estrogens, A) tablets, administered once daily for 90 days. Plasma concentration-time profiles for both total (conjugated and unconjugated) estrone and equilin, two major estrogens in Cenestin, were nearly superimposable between Day 1 (single dose) and Day 90 (multiple dose), indicating equivalent drug exposure from one dose to the next. For total estrone, the mean estimates of Cmax and AUC0-24 were 2.5 ng/ml and 35.0 ng x h/ml for Day 1 and 3.0 ng/ml and 39.8 ng x h/ml for Day 90, respectively. Similarly, Cmax and AUC0-24 mean values for total equilin were 1.4 ng/ml and 17.4 ng x h/ml after Day 1 and 1.5 ng/ml and 17.3 ng x h/ml after Day 90, respectively. The mean tmax value for total estrone was 8.3 hours on Day 1 and 8.6 hours on Day 90, indicating a slower rate of absorption. The average estimate for observed drug accumulation index for the 24-hour dosing interval was calculated to be 1.1 for total estrone and 1.0 for total equilin. These data, taken together, indicate a slow and steady rate of absorption, minimal drug accumulation at steady state, and consistent drug exposure between Cenestin doses.

A comparison of tibolone and hormone replacement therapy on coronary artery and myocardial function in ovariectomized atherosclerotic monkeys.

OBJECTIVE: Tibolone is used to prevent osteoporosis and to treat climacteric symptoms. The objectives of these studies were to measure and compare the effects of tibolone with hormone replacement therapy on coronary artery vascular reactivity and myocardial function and to relate these outcomes to treatment-induced plasma lipid/lipoprotein concentrations and atherosclerosis. DESIGN: One hundred forty-eight adult ovariectomized cynomolgus monkeys were fed an atherogenic diet for 24 months while receiving one of five oral treatments: no treatment (control, n = 31); conjugated equine estrogens (CEE), given at the equivalent of 0.625 mg/day ( n = 27); CEE (same dose) plus medroxyprogesterone acetate (MPA), given at the equivalent of 2.5 mg/day ( n = 29); low-dose tibolone (LoTib; 0.625 mg/day equivalent, n = 30); or high-dose tibolone (HiTib; 2.5 mg/day equivalent, n = 31). RESULTS: Quantitative coronary angiography showed that endothelium-mediated dilation was enhanced (17.5 +/- 5%, p = 0.002) in the CEE-treated group (but not other treatment groups) compared with the control. Both doses of tibolone and CEE reduced the incidence of dobutamine-induced ST-segment depression (LoTib: 33%, HiTib 25%, and CEE: 23%) compared to the control (79%) ( p = <0.05). Neither vascular reactivity nor dobutamine-induced myocardial ischemia were associated with treatment-induced changes in atherosclerosis or plasma lipid/lipoprotein concentrations. CONCLUSIONS: Tibolone, unlike CEE, has no benefit for endothelium-mediated dilation. Despite these differences, both tibolone and CEE reduced the incidence of myocardial ischemia, whereas CEE+MPA had no effect. It is speculated that tibolone may have direct effects on the myocardium that protect against myocardial ischemia.

The effects of six months of treatment with a low-dose of conjugated oestrogens in menopausal women.

OBJECTIVE: Hormone replacement therapy (HRT) is usually prescribed as medium- to high-dose formulations. Little is known, however, about dose-dependency of oestrogen effects on plasma hormone levels, markers of cardiovascular risk in lipid metabolism and the haemostatic system, or markers of bone turnover. SUBJECTS AND DESIGN: In an open trial, three groups of 12 or 13 healthy, non-obese postmenopausal women received conjugated equine oestrogens (CEE) for 6 months at doses of 0.3 mg/day (group 1), 0.6 mg/day (group 2) or 1.25 mg/day (group 3). From day 1 to day 10, CEE was administered alone, and from day 11 to day 21, in combination with 5 mg of medrogestone. Each treatment cycle was followed by a pause of 7 days. Fasting blood samples were obtained before treatment as well as on days 10, 21 and 28 of the first, third and sixth months on treatment. All results obtained on day 10 were grouped together as phase A, on day 21 as phase B, and on day 28 as phase C. MEASUREMENTS: Plasma concentrations of oestradiol (E), dehydroepiandrosterone sulphate (DHEA-S), total testosterone (T), FSH, PRL, sex hormone binding globulin (SHBG), type I procollagen propeptide (PICP) and the cross-linked carboxyterminal telopeptide of type I collagen (ICTP), total cholesterol, HDL-cholesterol, triglycerides (TG), apolipoprotein (apo) A-1, apo B, lipoprotein(a)[Lp (a)], fibrinogen, factor VIIc and plasminogen activator inhibitor 1 (PAI-1) were evaluated with commercially available kits. RESULTS: Dose-dependently, the three regimens increased E, SHBG and factor VIIc activity and decreased FSH, DHEAS, cholesterol, LDL-cholesterol and apoB. HDL-cholesterol and apoA-1 were slightly decreased in group 1 but increased in groups 2 and 3. The high CEE dosage in group 3 resulted in a significant increase of TG and decrease of Lp(a) and PAI-1. Markers of bone turnover were not significantly changed by any CEE dosage. CONCLUSIONS: Six months of treatment with 0.3 mg/day of conjugated equine oestrogen significantly lowers serum levels of total cholesterol and LDL-cholesterol without causing the adverse increases of triglycerides or factor VIIc, which were observed at higher doses. However, this low-dose treatment did not yield the maximal LDL-cholesterol lowering effect. Moreover, the positive effects of HRT on HDL-cholesterol, apolipoprotein A-I, lipoprotein (a) and plasminogen activator inhibitor-1 required at least the medium dose of 0.6 mg conjugated equine oestrogens per day. Therefore, further studies are needed to determine which dose of conjugated equine oestrogens has the optimal effect on cardiovascular risk and bone turnover.

Relationships of peri-partum, plasma concentrations of progesterone, oestrogens and 13,14-dihydro-15-ketoprostaglandin F2alpha in heifers and of anatomical measurements of dam and calf with difficulty of calving in early-bred Hereford x Friesian heifers.

Plasma concentrations of progesterone, oestradiol-17beta, oestrone, oestrone sulphate and PGFM have been measured daily during the first peri-partum period of 45 Hereford x Friesian heifers bred at 11 months of age. Anatomical measurements of dam and calf were also recorded. Twelve of the calvings were scored easy, 33 difficult. Each of five models (fitted by linear logistic regression) relating difficulty of calving to the hormonal and anatomical measurements, predicts with at least 94% accuracy the calving score (easy or difficult) among the calvings. The models predict that increases of progesterone concentration on the day before calving, of oestrone sulphate concentration on the day after calving and of heifer heart girth decrease the odds of difficult calving, whereas increases of heifer body length and of calf head circumference increase the odds of difficult calving.

Effects of age, season, and fertility status on plasma and intratesticular immunoreactive (IR) inhibin concentrations in stallions.

The nature of the relationship between inhibin and reproductive function in the stallion is yet to be elucidated. Blood and testes from 51 light horse stallions ranging in age from 2 mo to 25 years were collected during the breeding and nonbreeding seasons to study the effects of testicular maturation, aging, season, and fertility status on peripheral and intratesticular concentrations of Ir inhibin and other reproductive hormones. Of the 51 stallions, 12 age-matched stallions (6 fertile, 3 subfertile, and 3 infertile) were used in the fertility study. Blood samples were taken before castration and plasma stored at -20 degrees C for analysis of Ir inhibin, luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (T), estradiol (E2), and estrogen conjugates (EC) by radioimmunoassay (RIA). Testes were homogenized and testicular extracts prepared and frozen at -70 degrees C for analysis of Ir inhibin, T, E2, and EC by RIA. Plasma concentrations of Ir inhibin, LH, FSH, T, E2, and EC and intratesticular concentrations of Ir inhibin, T, E2, and EC increased with age (P < 0.01). The most dramatic effect appeared to be during testicular maturation. An aging effect was not observed in adult stallions. A seasonal effect was not detected for any of the plasma hormones, whereas for the intratesticular hormones the only change noted was an increase in T in the nonbreeding season (P < 0.05). Plasma Ir inhibin, E2, and EC were lower (P < 0.01) and gonadotropins higher (P < 0.05) in infertile stallions. Plasma T levels did not change. Intratesticular Ir inhibin concentrations tended to be lower (P < 0.1) in subfertile stallions and significantly lower (P < 0.01) in infertile stallions, whereas intratesticular steroid levels were not different among the three groups. In conclusion, plasma and intratesticular Ir inhibin concentrations seem to be affected by testicular maturation and fertility status.

Differential effect of carbamazepine and valproate monotherapy on plasma levels of oestrone sulphate and dehydroepiandrosterone sulphate in male epileptic patients.

Steroid sulphates such as oestrone sulphate (OE1S) and dehydroepiandrosterone sulphate (DHEAS) have been suggested to be of biological importance in different disease states such as breast cancer and atherosclerosis. Previous studies have shown that drugs such as aminoglutethimide and rifampicin that induce P450-dependent mixed-function oxygenases selectively suppress plasma OE1S levels. The aim of this study was to evaluate the influence of treatment with carbamazepine, an antiepileptic drug known to stimulate mixed-function oxygenases, on plasma levels of OE1S and DHEAS. We measured plasma OE1S and DHEAS together with other plasma oestrogens and androgens in male epileptic patients before and during carbamazepine monotherapy. Patients treated with valproate monotherapy acted as a control group. Treatment with carbamazepine decreased plasma OE1S levels from a mean value of 810.8 to 411.6 pmol/l (mean suppression to 50.7% of pretreatment levels, P < 0.001). Similarly, the ratio of OE1S to OE1 fell to 59.9% of pretreatment levels (P < 0.001)). DHEAS decreased from a mean level of 4.9 mumol/l before treatment to 3.0 mumol/l during carbamazepine therapy (mean reduction to 62.7% of pretreatment levels (P < 0.001), while the ratio of DHEAS to DHEA fell to 63.0% of pretreatment values (P < 0.01). No significant change in plasma levels of the other oestrogens or androgens measured was observed. Treatment with valproate caused a slight decrease in FSH levels (P < 0.05), but no change in any of the other hormones measured was observed. Studies are warranted to evaluate the possible effects of long-term treatment with carbamazepine on the risk of developing endocrine-sensitive tumours and cardiovascular disease and also the possible effects of alterations in plasma DHEAS on epileptic activity.

Effect of Toxoplasma gondii infection on the development of pregnancy and on endocrine foetal-placental function in the goat.

The effect of Toxoplasma gondii inoculation on pregnancy and on endocrine foetal-placental function in pregnant goats was studied. Five susceptible goats were inoculated subcutaneously with T. gondii bradyzoites at 71 +/- 2 days of gestation. Another five goats were used as controls. Plasma was analysed for progesterone, oestrone sulphate and 15-ketodihydro-PGF2 alpha. The condition of the foetuses was monitored by real-time ultrasonography. All inoculated goats aborted or delivered stillborn or weak kids 54-73 days after inoculation. None of the goats showed signs of general disease. In cases of foetal death, the ultrasound examination revealed that death occurred between day 1 and 12 before abortion or birth. The appearance of the foetuses varied from fresh to mummified, depending on the number of days between foetal death and expulsion. All five goats became serologically positive to T. gondii after inoculation. None of the goats used as controls aborted, but one goat delivered one mummified and one weak kid for unknown reasons. In inoculated animals an increase in 15-ketodihydro-PGF2 alpha levels in plasma and a subsequent tendency to a decrease in oestrone sulphate levels were observed from about day 40 after inoculation and until abortion or birth. High levels of 15-ketodihydro-PGF2 alpha were seen after foetal death. High levels of 15-ketodihydro-PGF2 alpha were not always followed by a drop in progesterone levels. The mean level of progesterone was slightly decreased after inoculation and onwards. The pattern of progesterone levels around abortion in the inoculated goats was very similar to the pattern around parturition in the control goats. However, 15-ketodihydro-PGF2 alpha levels were higher both before and after abortion in inoculated goats than in control goats. The level of oestrone sulphate did not increase in the inoculated group before abortion in contrast to the level in goats which delivered healthy kids. The patterns of changes in levels of 15-ketodihydro-PGF2 alpha and oestrone sulphate in inoculated animals indicate that the endocrine foetal-placental function was disturbed in most of the inoculated goats, probably due to the injury caused by the establishment and development of T. gondii infection in the placenta and foetus.

Reproducibility studies and interlaboratory concordance for assays of serum hormone levels: estrone, estradiol, estrone sulfate, and progesterone.

We conducted studies to measure sources of assay variability for estrone, estradiol, estrone sulfate, and progesterone for postmenopausal women (n = 5) and for women in the mid-follicular (n = 5) and mid-luteal (n = 5) phases of the menstrual cycle. A single blood sample from each woman was divided into 2.5-ml aliquots and stored at -70 degrees C, and sets of two aliquots were sent at monthly intervals to each of three laboratories (four for progesterone). Each aliquot was analyzed in duplicate. Thus, within each menstrual category, we were able to estimate the components of variance due to variation among women, variation among aliquots, variation among duplicate measurements, and variation among the 4 analysis days. Using the logarithm of assay measurements, we estimated the percentage of variance attributable to variation among women in each menstrual category, 100 rho, is the estimated intraclass correlation. For each assay, 100 rho exceeded 90% for mid-follicular and mid-luteal women. For postmenopausal women, values of 100 rho exceed 84% for estrone in two laboratories. Values of 100 rho were lower for progesterone in postmenopausal women, although a value of 84% was estimated from one laboratory. These studies indicate that estrogen assays over a period of 3 months permit reliable comparisons among women in a given menstrual category. Progesterone measurements are likewise reliable for women in the mid-follicular and mid-luteal phases but somewhat less satisfactory for postmenopausal women. These assessments of variability pertain only to laboratory techniques and do not allow for secular variation in intra-woman hormone levels. Moreover, although these measurements tend to be reliable enough for making comparisons among women, estimates of coefficients of variation for estrogens are about 10% for mid-follicular and mid-luteal phase women and about 11-20% for postmenopausal women. Coefficients of variation for progesterone are about 10% for mid-luteal, 20% for mid-follicular, and 30% for postmenopausal women.

Case-control study of endogenous steroid hormones and endometrial cancer.

BACKGROUND: It has been suggested that identified risk factors for endometrial cancer operate through a single etiologic pathway, i.e., exposure to relatively high levels of unopposed estrogen (estrogen in the absence of progestins). Only a few studies, however, have addressed this issue directly. PURPOSE: We assessed the risk of developing endometrial cancer among both premenopausal and postmenopausal women in relation to the circulating levels of steroid hormones and sex hormone-binding globulin (SHBG). The independent effect of hormones was assessed after adjustment for other known risk factors. METHODS: The data used in the analysis are from a case-control study conducted in five geographic regions in the United States. Incident cases were newly diagnosed during the period from June 1, 1987, through May 15, 1990. The case patients, aged 20-74 years, were matched to control subjects by age, race, and geographic region. The community control subjects were obtained by random-digit-dialing procedures (for subjects 20-64 years old) and from files of the Health Care Financing Administration (for subjects > or = 65 years old). Additional control subjects who were having a hysterectomy performed for benign conditions were obtained from the participating centers. Women reporting use of exogenous estrogens or oral contraceptives within 6 months of interview were excluded, resulting in 68 case patients and 107 control subjects among premenopausal women and 208 case patients and 209 control subjects among postmenopausal women. The hormone analyses were performed on blood samples obtained from case patients or from hysterectomy control subjects before surgery. The odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by use of an unconditional logistic regression analysis after we controlled for matching variables and potential confounders. All P values were two-sided. RESULTS: High circulating levels of androstenedione were associated with 3.6-fold and 2.8-fold increased risks among premenopausal and postmenopausal women, respectively, after adjustment for other factors (P for trend = .01 and < .001, respectively). Risks related to other hormone fractions varied by menopausal status. Among postmenopausal women, a reduced risk was associated with high SHBG levels and persisted after adjustment was made for obesity and other factors (OR = 0.51; 95% CI = 0.27-0.95). High estrone levels were associated with increased risk (OR = 3.8; 95% CI = 2.2-6.6), although adjustment for other risk factors (particularly body mass index) diminished the effect (OR = 2.2; 95% CI = 1.2-4.4). Albumin-bound estradiol (E2), a marker of the bioavailable fraction, also remained an important risk factor after adjustment was made for other factors (OR = 2.0; 95% CI = 1.0-3.9). In contrast, high concentrations of total, free, and albumin-bound E2 were unrelated to increased risk in premenopausal women. In both premenopausal and postmenopausal groups, risks associated with obesity and fat distribution were not affected by adjustment for hormones. CONCLUSION: High endogenous levels of unopposed estrogen are related to increased risk of endometrial cancer, but their independence from other risk factors is inconsistent with being a common underlying biologic pathway through which all risk factors for endometrial cancer operate. IMPLICATIONS: Further research should focus on alternative endocrinologic mechanisms for risk associated with obesity and body fat distribution and for the biologic relevance of the increased risk associated with androstenedione in both premenopausal and postmenopausal disease.

Hormonal indicators of pregnancy in llamas and alpacas.

OBJECTIVE: To determine concentrations of estrone sulfate in serum, estrone sulfate in urine, relaxin in serum, and progesterone in serum in pregnant llamas and alpacas and to assess the potential of these hormones as pregnancy indicators. DESIGN: Prospective study. ANIMALS: 19 parous pregnant camelids (8 llamas and 11 alpacas). PROCEDURE: Estrone sulfate concentrations (in serum and in urine) and progesterone concentrations (in serum) were determined by enzyme immunoassay. Relaxin concentrations (in serum) were measured by radioimmunoassay. Serum and urine samples were collected daily for the first 30 days after breeding and, thereafter, once weekly until parturition. RESULTS: Estrone sulfate concentrations (in serum and in urine) peaked twice during pregnancy. The first took place 21 days after breeding and the second during the last month of pregnancy. Relaxin concentrations increased at 3 months of gestation to > 20 ng/mL, decreased at 5 months to 5 ng/mL, then increased from 8 months of pregnancy until parturition. Progesterone concentrations were detectable 4 days after breeding and were maintained > 2 ng/mL throughout pregnancy. CLINICAL IMPLICATIONS: The first increase in estrone sulfate concentration over basal values may indicate early interaction between mother and embryo, whereas the second increase may reflect fetal viability. Use of estrone sulfate concentration to diagnose pregnancy in llamas and alpacas is highly dependent on time of sampling. Relaxin concentration in serum is a superior indicator of pregnancy after the second month in the Ilama and alpaca because its existence is suggestive of interaction between mother and fetus, and concentrations are greater than basal values for a long period of pregnancy. Progesterone is not a direct product of the embryo or fetus and only indirectly confirms a diagnosis of pregnancy.

Establishment of a reliable extraction method of estrone sulfate from bovine plasma for detection of the peripheral level during the regular estrous cycle by radioimmunoassay.

A simple extraction and assay technique of estrone sulfate in bovine blood was developed with the object of detecting the peripheral level of estrone sulfate in a normal estrous cycle or in early pregnancy. Estrone sulfate in bovine plasma was extracted with a small reversed phase cartridge. The steroid conjugate retained in the cartridge was eluted with 40% (v/v) methanol. Estrone sulfate was separately recovered from other steroids by the stepwise increase in methanol concentration in the elution solvent. The recoveries of estrone sulfate eluted with 40% methanol were more than 90%, irrespective of the applied plasma volume. The concentration measured by radioimmunoassay with the eluent of 40% methanol was consistent for plasma extraction volumes of 0.5-2.0 ml. The change of estrone sulfate in bovine peripheral plasma during the regular estrous cycle was determined with a small reversed phase cartridge for extraction and 40% methanol for elution. The change in estrone sulfate was found to be similar to the change of estrone and estradiol-17 beta. The concentration of estrone sulfate was not higher than that of both estrogens in cattle.

Patterns of hormone secretion throughout pregnancy in the one-humped camel (Camelus dromedarius).

Peripheral serum samples were collected from 8 pregnant dromedary camels and hormone secretion patterns were examined at specific time intervals. Mean serum progesterone concentrations began to rise 3-4 days after ovulation and remained reasonably constant at 3-5 ng mL-1 for the first 90-100 days of gestation. Concentrations then showed a definite fall, but thereafter remained constant again at 2-4 ng mL-1 throughout the rest of pregnancy. In contrast, serum oestrogen concentrations showed pronounced fluctuations during the first 100 days of gestation. Mean oestradiol-17 beta concentrations increased at around Day 50 to about 100 pg mL-1 and then remained relatively constant from Day 90 to Day 300. Mean oestrone sulfate concentrations, however, showed two definite peaks in early gestation, each reaching about 10 ng mL-1, with the first peak occurring around Day 25 and the second peak around Day 75. Oestrogen production then remained fairly constant until around Day 300, after which concentrations of both oestrone sulfate and free oestradiol-17 beta rose steeply over the next 80 days to reach mean peak values of 46 ng ML-1 and 518.7 pg mL-1, respectively, at the time of parturition. Concentrations of 13,14 dihydro-15-keto prostaglandin F2 alpha (PGFM) remained low and reasonably steady at 100-200 pg mL-1 during the first 320 days of pregnancy; thereafter, PGFM concentrations rose steeply over the next 50 days, before an explosive further increase to a peak of 1900 +/- 141 pg mL-1 mean +/- sem on the day of calving. These results suggest that, as in the cow, a major change in steroid synthetic capability and/or enzyme content of the placenta may occur at around 80% (Day 300) of gestation in the pregnant camel.