Free Estrone Research Articles

Biochemical classification diagnosis of polycystic ovary syndrome based on serum steroid hormones

Polycystic ovary syndrome (PCOS) is a metabolic disorder with clinical heterogeneity. PCOS women with non-hyperandrogenemia (NA) might be misdiagnosed due to a lack of diagnostic markers. This study aims to systematically analyze the differences in steroid hormones between PCOS women with hyperandrogenemia (HA) and NA, and to screen classification diagnosis models for PCOS. The serum samples from 54 HA-PCOS, 79 NA-PCOS and 60 control women (Non-PCOS) aged between 18 and 35 were measured by an integrated steroid hormone-targeted quantification assay using LC-MS/MS. The levels of serum androgens, corticosteroids, progestins and estrogens in the steroid hormone biosynthesis pathway were analyzed in PCOS and Non-PCOS women. Eight machine learning methods including Linear Discriminant Analysis (LDA), K-nearest Neighbors (KNN), Boosted Logistic Regression (LogitBoost), Naive Bayes (NB), C5.0 algorithm (C5), Random Forest (RF), Support Vector Machines (SVM), and Neural Network (NNET) were performed, evaluated and selected for classification diagnosis of PCOS. A 10-fold cross-validation on the training set was performed. The whole metabolic flux from cholesterol to downstream steroid hormones increased significantly in PCOS, especially in HA-POCS women. The RF model was chosen for the classification diagnosis of HA-PCOS, NA-PCOS, and Non-PCOS women due to the maximum average accuracy (0.938, p<0.001), AUC (0.989, p<0.001), and kappa (0.906, p<0.001), and the minimum logLoss (0.200, p<0.001). Five steroid hormones including testosterone, androstenedione, total 2-methoxyestradiol, total 4-methoxyestradiol, and free estrone were selected as the decision trees for the simplified RF model. A total of 37 women were included in the validation set. The diagnostic sensitivity for HA-PCOS, NA-PCOS, and Non-PCOS was 100 %, 93.3 % and 91.7 %, respectively. HA-PCOS, NA-PCOS, and Non-PCOS women showed obvious different steroid hormone profiles. The simplified RF model based on two androgens and three estrogens could be effectively applied to the classification diagnosis of PCOS, further reducing the missed diagnosis rate of NA-PCOS.

Local hormonal status of tumor and adjacent tissues in patients with melanoma depending on their gender.

e22084 Background: Gender is an important independent prognostic factor for cutaneous melanoma incidence, and survival in women is better. The purpose of the study was to determine the content of sex steroids and prolactin in tumor, perifocal and resection line tissues in male and female patients with melanoma. Methods: The study included 13 men and 22 women with cutaneous melanoma (M) pT1-2N0M0. Levels of free testosterone (fT), estradiol (E2), estrone (E1), progesterone and prolactin were measured by ELISA in M, perifocal (P) and resection line (RL) tissues after surgical treatment. The average age of patients was in men 54±3.56 years (median age 53, 32-81), in women 65±2.67 years (median age 63, 39-82). Skin tissues obtained from 20 non-cancer patients after plastic surgery served as the control. Results: In M of women, levels of fT, E2 and E1 were elevated on average by 1.3 times, while in men fT was decreased by 1.7 times, and estrogens were increased – E2 by 1.7 and E1 by 3.7 times, compared to the corresponding control levels. In women, fT in P tissues was increased by 1.6 times, while parameters in RL were similar to control values. In men, fT in P and RL tissues was decreased by 3.8 and 2.3 times respectively, and E2 was increased by 1.6 and 1.3 times respectively. E1 in P tissues was decreased by 1.7 times, in RL – similar to control levels. Conclusions: M in patients of both genders has an altered hormonal profile characterized by hyperestrogenia, with the prevalence of E1 and androgen deficiency in men. The expansion of the “tumor field” due to changes in the hormonal profile of P and even RL tissues was established only in male patients with the same morphological prevalence of the process, which may be one of the reasons for the more aggressive tumor course.

Role of testosterone synthesized by skin melanocytes in preventing malignant transformation of nevi.

e21066 Background: Melanocytes are involved into the synthesis and metabolism of steroid hormones in the skin. Cutaneous melanoma in 75% of cases occurs in congenital or acquired pigmented nevi. There are no studies comparing local hormonogenesis in nevi and melanomas. The purpose of the study was a comparative analysis of hormone levels in tissues of dysplastic nevi and cutaneous melanoma (pТ1-2N0M0). Methods: Levels of prolactin (PRL), progesterone (P4), total and free testosterone (T and fT), estrone (E1) and estriol (E3) and sex steroid-binding globulin (SSBG) were studied by ELISA in 17 samples of рТ1-2N0M0 melanoma and in 23 samples of dysplastic nevi. Intact tissues (n = 15) obtained from non-cancer patients during surgical treatment was used as the control. Results: Levels of T in nevi, compared to intact tissues, were 1.4 times higher, fT – 8.7 times higher, while SSBG content was 1.9 times lower; E3 was 1.6 times higher, PRL – 1.4 times lower, and levels of E1 in nevi were similar to the values in intact tissues. рТ1-2N0M0 melanomas, compared to intact tissues, demonstrated local androgen imbalance: T levels were decreased by 1.8 times, while fT exceeded the norm by 1.8 times, and SSBG – by 6 times. E1 content increased by 1.6 times, E3 decreased by 2.8 times. The E1/E3 ratio in nevi was reduced by 1.6 times, while in melanoma it was increased by 4.4 times. The T/E1 ratio in nevi was increased by 1.4 times, and in melanoma it was decreased by 2.8 times. Levels of PRL and P4 in melanomas, nevi and in intact tissues did not differ significantly. Conclusions: Melanoma was characterized by hyperestrogenia due to increased levels of E1 and low E3 concentrations which caused malignant transformation of melanocytes. Most likely, in melanoma spent SVT estrone synthesis, as evidenced by increase in the E1 / E3 and decrease T / E1.Apparently, fT in melanoma is used for estrogen synthesis, as indicated by the E1/E3 increase and decrease in the T/E1 ratio. Increased E1 synthesis can contribute to the realization of estrogen genotoxic effects. These mechanisms are absent in tissues of nevi. Hyperandrogenism in nevi probably prevents malignant transformation due to low aromatase activity.

Sex steroids, sex-binding globulin, and prolactin in tissues of adenocarcinoma and esophageal squamous cell carcinoma.

79 Background: Some researchers suggest that squamous cell carcinoma (SCC) and adenocarcinoma of the esophagus (ACE) are characterized by different pathogenesis, epidemiology and tumor biology, and therefore require different therapeutic strategies. The purpose of the study was to analyze local hormonal status in malignant esophageal tumors and surrounding tissues depending on the histogenesis. Methods: Levels of sex steroids – free testosterone (fT), estrone (E1), estriol (E3), prolactin (PRL) and sex steroid-binding globulin (SSBG) were studied by the standard ELISA methods in tumor tissue, perifocal zone and resection line of 39 patients aged 58-74 years: 27 SCC, 12 ACE, stage II, G2, pT1-2N1M0. Results: Differences were found in local hormonal content in all studied samples dependint on the tumor histotype. Levels of SSBG, PRL and E1 in ACE were higher than in SCC by 1.3, 3.3 and 1.4 times, respectively, while fT concentration was 2.4 times lower. Levels of PRL, E1 and E3 in perifocal zone of ACE compared to SCC were higher by 2.8, 3.3 and 3.1 times, and fT was 1.3 times lower. Resection line of ACE differed from that of SCC by higher tissue concentrations of SSBG – by 1.3 times, PRL – by 1.5 times, E1 – by 1.3 times, E3 – by 1.7 times and a lower level of fT – by 1.5 times. As a result, fT/E1 ratios in ACE and surrounding tissues were on average 3 times lower than in corresponding SCC samples. Conclusions: Levels of hormones in esophageal tumors and surrounding tissues depend on the histogenesis. ACE was characterized by hyperestrogenism in esophageal tissues along with a high prolactin concentration, while SCC – by hyperandrogenism with a low PRL level. Different pathogenesis of SCC and ACE was demonstrated by the fact that hormonal profile in both tumor and resection line depended on the tumor histology.

Gender differences in hormonal statuses of patients with esophageal squamous cell carcinoma.

85 Background: Esophageal squamous cell carcinoma (ESCC) is 4-8 times more frequent in men than in women, with poorer prognosis. The purpose of the study was to analyze systemic and local hormonal statuses in patients with ESCC in dependence on their gender. Methods: The study included 34 ESCC (G2, рT1-2N0-1M0) patients: 21 men and 13 women. 11 men (52.4%) had lymph node metastases. Levels of sex steroids – total (T) and free (fT) testosterone, progesterone (P4), estradiol (E2), estrone (E1), prolactin (PRL), LH, FSH and sex steroid-binding globulin (SSBG) – were studied in the peripheral blood, tumor and resection line by the standard RIA and ELISA methods. Results: Men showed a decrease in the blood T concentration by 1.4 times, P4 by 2 times, and E2 increase by 2.5 times, while women showed 1.3 times increase in T and 2 times decrease in P4. Metastases in men were accompanied by an increase in blood levels of anterior pituitary hormones: PRL by 2.5 times, LH by 2.3 times and FSH by 2.2 times compared to patients without metastases. Analysis of the local saturation with sex hormones in visually unchanged esophageal tissues of ESCC patients did not reveal any significant gender difference. However, women were characterized by a higher content of anterior pituitary hormones, PRL, LH and FSH, in esophageal tissues compared to men. Men with metastases showed local hyper-androgenization of tumor and surrounding tissues, as the fT to E1 ratio was increased. Conclusions: The results confirmed the data on T-stimulation of malignant growth in the esophagus and the possible protective effect of estrogens. The free testosterone to estrogens ratio in esophageal tissues can probably serve as one of prognostic factors for the disease course.

PROFILE OF SEX STEROIDS AT EARLY STAGES OF LIVER METASTASIS FROM SARCOMA 45 IN MALE RATS

Background . Sex hormones are involved in pathogenesis of cancer of the reproductive organs; however, their role in the development of other cancers is poorly studied. Objectives. Study of metabolism of sex hormones in the testes, prostate, tumor (TR), metastases (MTS) and blood serum (BS) at the early stages of liver metastasis. Material and methods. The study included 28 white out bred male rats. Levels of estradiol (E 2 ), total testosterone (T), prolactin (PRL) and progesterone (P 4 ) were studied in the liver by radioimmunoassay, and free testosterone (fT), estrone ( Е 1 ) and sex steroid-binding globulin(SSBG)were studied by ELISA 1-2 weeks (before TR occurrence in the spleen) and 5 weeks (before MTS occurrence in the liver) after the injection of TR cells into the spleen. Results. Appearance of TR in the spleen was preceded by increased Е 1 (by 3.4 times) and fT (by 2.5 times) and decreased P 4 (by 4.5 times) in week 1 and increased PRL (by 1.7 times) and decreased fT (by 3.4 times) in week 2. Already formed TR showed E 1 increase (by 8.8 times). Occurrence of MTS was preceded by increased E 2 (by 1.2 times) and decreased P 4 (by 3.1 times) in the liver. Conclusions. E isthe main element of the hormonal profile of primary TR. Е 1 creates conditions for the formation of the metastatic field in the liver where later MTS develop.

Ovarian follicular activity during late gestation and postpartum in guanaco (Lama guanicoe).

This study evaluated ovarian activity in late gestation and post-partum in guanacos in captivity. Follicular dynamics was monitored every second day from 40 days before and other 40 after delivery by transrectal sonography and by plasma steroids concentrations. Seven out of eight (87.5%) of gestating females presented ovarian follicular activity under progesterone levels >3 nmol/l with maximum follicular size of 8.42 ± 0.83 mm from days 23 to 1 before delivery. After delivery, all females have follicular wave development from day 0 to 38, with larger follicular size and longer follicular wave phases and interwave interval when compared with pre-partum data. During post-partum period, there was a close relationship between follicle size and estradiol-17β concentration, with r = 0.69 at the beginning of growth phase and r = 0.86 in association with the largest dominant follicle. Plasma estradiol-17β concentration varied from 11.92 to 198.55 pmol/l. Plasma estrone sulfate, free estrone and progesterone returned to baseline concentrations during peripartal period and remained basal thereafter. The results described follicular activity during late gestation and early post-partum period. These findings provide relevant information to understand physiological changes occurring during this reproductive key period in seasonal breeders with long gestation duration as New and Old World camelids.

Circulating Estrone Levels Are Associated Prospectively With Diabetes Risk in Men of the Framingham Heart Study

OBJECTIVEIn postmenopausal women and preclinical murine models, estrogen administration reduces diabetes risk; however, the relationship of estradiol and estrone to diabetes in men is poorly understood. We determined the relationship between circulating estradiol and estrone levels and diabetes risk in community-dwelling men of the Framingham Heart Study (FHS).RESEARCH DESIGN AND METHODSCross-sectional relationships of estradiol and estrone levels with diabetes were assessed at examination 7 (1998–2001) in FHS generation 2 men (n = 1,458); prospective associations between hormone levels at examination 7 and incident diabetes were assessed 6.8 years later at examination 8. Type 2 diabetes mellitus was defined as fasting glucose >125 mg/dL, medication use, or both. Estradiol, estrone, and testosterone levels were measured with liquid chromatography–tandem mass spectrometry, and free estradiol and estrone were calculated.RESULTSIn cross-sectional models, men with elevated estrone and estradiol had 40% and 62% increased likelihoods of existing diabetes per cross-sectional doubling of estrone and estradiol levels, respectively. Free estrone (cross-sectional odds ratio 1.28 [95% CI 1.02–1.62], P = 0.04) was associated with impaired fasting glucose at examination 7. There was an increase in risk of existing diabetes with increasing quartiles of total and free estrone and estradiol and an increase in risk of incident diabetes with increasing quartiles of estrone levels. In multivariate longitudinal analyses, a twofold increase in total or free estrone levels at examination 7 was associated with 77 and 93% increases, respectively, in odds of incident diabetes at examination 8.CONCLUSIONSAlthough both estradiol and estrone exhibit cross-sectional associations with diabetes in men, in longitudinal analyses estrone is a more sensitive marker of diabetes risk than is estradiol.

B-8. 妊婦血中Free〈Estrone+Estradiol〉のRIA

B-8. 妊婦血中Free〈Estrone+Estradiol〉のRIA

Expression and Activity of Steroid Sulphatase in the Boar Testis

Oestrogens are essential for male fertility targeting the testicular-epididymal compartment. However, the underlying mechanisms are only vaguely known and species specificities must be considered. The boar has a remarkably high testicular-oestrogen output, with the biologically inactive oestrone-sulphate being the major oestrogen occurring in the testicular vein. In the boar testis and epididymis, activity of steroid sulphatase (StS) and oestrogen sulphotransferase has been demonstrated. Thus apart from their synthesis in Leydig cells, provision of biologically active free oestrone seems also to depend on the activity and localization of these enzymes. Our aim was to establish expression patterns and activity of StS in boar testis. Testes were randomly collected from healthy boars and allotted to five age groups, five animals in each, aged 50, 100, 150, 200 and 250 days. Three extra boars aged over 250 days were castrated to obtain fresh tissue for enzyme activity tests. Immunohistochemistry detected StS only in the cytoplasm of Leydig cells and - except for day-50 group in which 65.1 +/- 4.9% (X +/- SD) of the cells were positive - expression was constant with virtually all the cells staining positive. RT-PCR and in situ hybridization confirmed expression and localization of StS mRNA. The V(max) and K(m) value (X +/- SD) for StS was 24.05 +/- 0.3 fmol/s/microg protein and 2.15 +/- 0.12 microM. These data suggest that StS within the Leydig cells of the boar is involved in modulation of testicular oestrogen bioavailability and that the site of sulpho-conjugation is not the testis but a different compartment of the testes-epididymidis complex.

Modulation of porcine cytochrome P450 enzyme activities by surgical castration and immunocastration

The present study aimed to evaluate some cytochrome P450 metabolic enzyme activities in hepatic microsomes prepared from entire male pigs (uncastrated pigs), surgically castrated pigs and pigs immunized against gonadotropin-releasing hormone (immunocastrated pigs). The activities of the following enzymes were measured: ethoxyresorufin O-deethylase (EROD, CYP1A1/1A2), methoxyresorufin O-deethylase (MROD, CYP1A2), pentoxyresorufin O-depentylase (PROD, CYP2B), coumarin hydroxylase (COH, CYP2A) and p-nitrophenol hydroxylase (PNPH, CYP2A/2E1). The total cytochrome P450 contents were not affected by either surgical or immunocastration. Hepatic microsomal activities for EROD, PROD, COH and PNPH were lower in entire male pigs compared with surgically castrated and immunocastrated pigs (P < 0.05). Surgically and immunocastrated male pigs were similar with respect to EROD, MROD, PROD and COH activities (P > 0.05), whereas surgically castrated pigs exhibited lower PNPH activity compared with immunocastrated pigs (P = 0.029). The effect of different concentrations of testicular steroids – testosterone, 17β-estradiol, free estrone and androstenone – on enzyme activities was evaluated by in vitro microsomal study. Testosterone at the concentration of 8 pmol/ml inhibited EROD activities and estradiol-17β at the concentration of 1.8 pmol/ml inhibited PROD activities in hepatic microsomes from surgically castrated pigs. The highest concentration of androstenone (7520 pmol/ml) inhibited COH activities, whereas a 42-fold lower concentration of androstenone (180 pmol/ml) stimulated COH activities in surgically castrated pigs. Both free estrone (3.5 pmol/ml) and androstenone (55 pmol/ml) inhibited EROD activities in microsomes from entire male pigs. Stimulation of COH activities by the highest dose of free estrone (18 pmol/ml) was recorded in microsomes from entire male pigs. However, these effects of steroids were not concentration-dependent and the maximum extent did not exceed ±15% variation compared with the controls. There was no inhibition of PNPH activities in the hepatic microsomes from either entire or castrated pigs. In conclusion, we showed that EROD, PROD, COH and PNPH activities were lower in entire male pigs compared with those in surgically and immunocastrated pigs. Direct inhibition by the testicular steroids – testosterone, 17β-estradiol, free estrone and androstenone – was not the primary cause of the reduced enzyme activities.

Effect of polymorphism in the porcine cytochrome b5 (CYB5A) gene on androstenone and skatole concentrations and sexual development in Swedish pig populations

The present study investigated the presence of a single-nucleotide polymorphism (G > T) at base −8 upstream of ATG in 5′ untranslated region of cytochrome b5 (CYB5A) gene in Swedish pig populations and evaluated the significance of this polymorphism for androstenone and skatole levels, sexual development and performance parameters in pigs. Frequencies of the T allele were 6.7% for Swedish Yorkshire × Landrace crossbred pigs (n = 245), 6.5% for Swedish Yorkshire (n = 99) and 12.8% for Landrace breed (n = 74). No deviations from Hardy–Weinberg equilibrium were observed in the investigated populations. In Swedish Yorkshire × Landrace crossbred entire male pigs (n = 193), plasma samples were analysed for skatole, androstenone, testosterone and oestrone sulphate, and fat samples were analysed for androstenone, skatole and free oestrone. Additionally, testis weight and bulbourethral gland length for crossbred pigs were recorded. Plasma androstenone levels were significantly lower in the G/T genotype at 90 kg live weight compared with the wild G/G genotype at the same live weight (P = 0.006). In heavier pigs, plasma androstenone levels did not differ between genotypes (P = 0.382). Fat androstenone levels were not affected by CYB5A genotype (P = 0.252). Skatole levels in the G/T genotype at 115 kg live weight were lower compared with those in the G/G genotype in plasma (P = 0.048) and fat (P = 0.028), although no differences were observed in lighter pigs. Testis weight, bulbourethral gland length, testosterone and oestrone sulphate levels in plasma, and oestrone levels in fat were not affected by genotype. We concluded that the presence of the T allele in the CYB5A gene resulted in lower androstenone levels in plasma, and lower skatole levels in fat and plasma; this reduction, however, was dependent on the live weight of the animals. Reproductive hormones and growth rate did not differ between the pigs of different genotypes, whereas a higher lean meat content was found in the G/T genotype in comparison with the G/G genotype. The practical application of those results in Sweden is doubtful because of lack of the effect on androstenone in fat and the low frequency of the T allele in the studied Swedish pig populations.

In the rat, estrone sulphate is the main serum metabolite of oral oleoyl-estrone

Two different oral doses of oleoyl-estrone: 1 and 10 nmol/g a day were given once to male Wistar rats. The serum levels of free estrone, estrone sulphate, estradiol, and acyl-estrone were measured at intervals up to 72 h after the gavage. Oleoyl-estrone was rapidly absorbed; with the 1 nmol/g dose no changes were observed in plasma acyl-estrone but levels increased dramatically with 10 nmol/g, peaking at 6 h; high acyl-estrone levels were maintained up to 24 h, returning to normalcy at 48 h. With the 10 nmol/g dose, free estrone at most doubled its levels but estrone sulphate concentrations rose by one order of magnitude; in both cases, the increases soon (2 h) reached a plateau that was maintained for almost two days. Estradiol levels remained unchanged except for a transient peak at 2 h at the 10 nmol/g dose. The relationship between free estrone and its sulphate was linear, and those of estrone and estrone sulphate versus acyl-estrone showed the existence of an upper serum concentration limit for both molecules. The results hint at estrone sulphate being an important metabolite of oleoyl-estrone disposal, confirm the limited estrogenic response to oleoyl-estrone administration and agree with a rapid absorption and disposal of oleoyl-estrone, nevertheless maintaining high circulating levels of the ester for a time after its oral administration.

Histopathologic findings in women with postmenopausal bleeding: implication for endometrial thickness and circulating levels of sex steroid hormones

The aim of this study is to compare the relationship between estrone (E1), estradiol (E2), androgens, and prolactin blood levels on the one hand, and endometrial thickness and related histopathologic results on the other, in postmenopausal women admitted with uterine bleeding. The study was conducted in Gazi University School of Medicine, Obstetrics and Gynecology Clinic with a total of 128 patients. The study group consisted of 64 postmenopausal patients admitted with uterine bleeding, whereas the control group consisted of 64 healthy postmenopausal women. Vaginal sonography was performed to evaluate the endometrial thicknesses of the patients. Serum levels of free testosterone, androstenedione and estrone (E1) were determined by radioimmunoassay while serum estradiol (E2), prolactin, and dehydroepiandrosterone sulfate (DHEA-S) levels were evaluated by chemiluminescent method. The median age, duration of menopause, menopausal age and gravidity, and parity did not differ between women with postmenopausal bleeding and the control group (P > 0.05). However, DHEA-S level was lower (P < 0.05) and endometrial thickness was greater in the study group than the control group (P < 0.05). Furthermore, the study identified that median endometrial thickness of the patients in atrophic endometrium group was less than the endometrial hyperplasia and endometrium carcinoma group (P < 0.05). In the current study, all these hormones seemed to be indifferent between groups of endometrial cancer and other pathological results. Based on our results regarding the safe margin of endometrial thickness in women with postmenopausal bleeding, it seems justifiable to refrain from curettage in patients with an endometrium of < or =4 mm.

Boar Taint is Related to Endocrine and Anatomical Changes at Puberty but not to Aggressive Behaviour in Entire Male Pigs

This study aimed to describe the association between incidence of boar taint and pubertal changes in gonadal hormones, size of reproductive organs and aggressive behaviour in entire male pigs. In total, 111 entire male pigs were included in the study. Sampling was performed first at 90 kg live weight (LW) and, then, at 115 kg LW. Variables measured were skatole and androstenone levels in plasma and fat, testosterone and oestrone sulphate in plasma, free oestrone in fat, weight of testes and length of bulbourethral glands. Aggressive interactions between pigs were registered when a limited amount of feed was provided to the pigs prior to routine feeding. The number of initiated interactions (attacks) and the difference between number of initiated and received interactions (relative attacks) were calculated for each pig. Multivariate analysis revealed that gonadal hormones and reproductive organ size influenced prevalence of boar taint, accounting for 30% of the variation in skatole levels in fat and for 37% of the variation in androstenone levels in fat. These relations were independent of aggression levels in entire male pigs. Skatole levels were influenced by the levels of oestrone sulphate in plasma and free oestrone in fat, but not levels of plasma testosterone. Pigs with testes weight below 565 g and a bulbourethral gland length <90 mm did not produce high amounts of skatole; therefore, these values can be used as a threshold level to detect pig carcasses with low skatole levels. High androstenone levels could not be predicted by measuring reproductive organ sizes. More research is required to develop a rapid and accurate method for the analysis of carcasses of entire male pigs.

Free Oestrone in Adipose Tissue and its Relation to Androstenone and Skatole in Entire Male Pigs

Relationship between free oestrone and boar taint compounds in adipose tissue were studied in two groups of entire male pigs of different breeds. Group A consisted of 33 entire crossbred male pigs (dam Yorkshire and sire backcross Yorkshire x Wild Boar, generation seven). Group B consisted of 194 entire male pigs of crossbreeds between Swedish Hampshire (H) and Finnish Landrace (L), LH x H, H x LH, LH x LH (dam x sire). The measurements of free oestrone in adipose tissue were performed with a new method developed and validated in our laboratories. The standard curve was linear for concentrations of free oestrone ranging from 0.13 to 5.10 ng/g. The method exhibited parallelism of results between serial dilutions and a mean recovery of 97 +/- 13.7%. Intra-assay variations for samples with concentrations of free oestrone from 0.67 to 2.08 ng/g were from 9.23 to 11.94%. Inter-assay variations for the samples with concentrations of free oestrone from 0.89 to 2.96 ng/g were from 3.78 to 10.11%. The levels of free oestrone in fat from group A were well correlated with fat levels of androstenone (r = 0.66; p < 0.001) and levels of oestrone sulphate in peripheral plasma collected at the same time as the fat (r = 0.74, p < 0.001). The levels of free oestrone in fat from group B were significantly correlated to fat levels of androstenone (r = 0.68, p < 0.001) and skatole (r = 0.29, p < 0.001). In group B, age-related differences in fat levels of free oestrone, androstenone and skatole were studied. Free oestrone and skatole levels increased simultaneously at the age of 22 week (p < 0.05 for both), and androstenone levels increased at the age of 26 week (p < 0.05). It was suggested that the levels of free oestrone in adipose tissue might be used for the evaluation of hormonal status of male pigs as an alternative to plasma levels of testicular hormones. The levels of free oestrone might be involved in the regulation of skatole levels in fat as indicated by both the simultaneous increases in skatole and free oestrone levels in fat and positive correlation between skatole and free oestrone.

Tamoxifen does not prevent the mobilization of body lipids elicited by oleoyl-estrone

Oleoyl-estrone is a powerful, slimming adipose tissue-derived signal that has biological effects widely opposed to those of its estrone moiety. The present experiment was designed to determine whether oleoyl-estrone effects on body energy are mediated by the estrogen receptor, blocked with the antagonist tamoxifen. Male Wistar rats were given daily oral doses of 10 μmol/kg d of oleoyl-estrone in oil containing 0 or 0.40 mg/kg d of tamoxifen. The data were compared with controls receiving only oil or 50 nmol/kg d of free estrone. After 10 days, the rats were killed, and their body composition and plasma metabolites and hormones were analyzed. Rats receiving estrone increased their body energy and lipid content compared with controls. Both groups of oleoyl-estrone-treated rats lost body weight, energy, and lipid; the losses in the rats receiving tamoxifen alone were less marked than in those receiving oleoyl-estrone. No significant changes in plasma glucose or triacylglycerols were observed. The patterns of change of estrone sulphate, estradiol, and oleoyl-estrone were consistent with a noticeable hydrolysis of oleoyl-estrone. The lack of differences in the fat mass in oleoyl-estrone-treated rats irrespective of the presence of tamoxifen suggested that the estrogenic pathway was not responsible for the slimming effects observed. Thus, it can be concluded that oleoyl-estrone effects are not mediated through its conversion to estrone or estradiol acting through the estrogen receptor. Tamoxifen partly mimicked the slimming effects of oleoyl-estrone; this could be speculatively explained by tamoxifen acting through the oleoyl-estrone signalling pathway.

Technical Note: Measurement of Total Estrone Content in Foods. Application to Dairy Products

Estrone is a powerful growth-inducing hormone that is present in milk, mainly in the form of fatty acid esters, at concentrations that promote growth in experimental animals. We present here a method useful for the measurement of this natural hormone in foods and applied it to several common dairy products. Samples were frozen, finely powdered, and lyophilized then extracted with trichloromethane/methanol; the dry extract was saponified with potassium hydroxide. The free estrone evolved was extracted with ethyl acetate and was used for the estimation of total estrone content through radioimmunoassay. Application of the method to dairy products showed high relative levels of total estrone (essentially acyl-estrone) in milk, in the range of 1μM, which were halved in skimmed milk. Free estrone levels were much lower, in the nanomolar range. A large proportion of estrone esters was present in all other dairy products, fairly correlated with their fat content. The amount of estrone carried by milk is well within the range, where its intake may exert a physiological response in the sucklings for which it is provided. These growth-inducing and energy expenditure-lowering effects may affect humans ingesting significant amounts of dairy products.

The bovine placenta; a source and target of steroid hormones: observations during the second half of gestation

Apart from estrone-3-sulfate (E1S) the bovine placenta produces progesterone (P4), though the corpus luteum is the major source of P4 responsible for maintaining pregnancy. So far the biological function of placental steroids in cattle is largely unknown. However, since the local availability of free estrone (E1) in the placenta seems to be controlled by sulfatase and sulfotranferase, the hypothesis was developed that placental estrogens and P4 might act as local regulatory factors. To test for such a function placentomes from 150, 220, 240, 270 days (D) pregnant and parturient cows were screened immunohistochemically for progesterone and estrogen receptors (PR, ER). PR were found at all stages in the caruncle in stromal cells and capillary pericytes but only at parturition in arterial walls. Percentage of PR-positive caruncular stromal cells (CSC) increased ( P<0.05) from 51.8±2.6% at D150 to 58.9±1.8% at parturition. ER were detected in CSC, caruncular epithelial (CE) cells and in caruncular capillary pericytes. Mean percentage of ER-positive CSC decreased from 39.0±5.9% in pregnant cows to 17.5±8.3% at parturition ( P<0.05). In CE all cells exhibited positive signals with the exception of those immediately surrounding large primary chorionic villi. Proliferation was assessed immunohistochemically by determining the percentage of Ki67-antigen positive cells. Highest values ( P<0.001) were obtained for CE (58.0–68.3%), followed by the trophoblast (23.3–25.4%), CSC (10.6–45.3%) and the stroma of the chorionic villi (2.9–10.5%). A transient depression of proliferation in CSC between D150–270 ( P<0.05) paralleled local estrogen tissue concentrations. The results suggest that placental estrogens and P4 are important factors controlling caruncular growth, differentiation and function.

Intestinal handling of an oral oleoyl-estrone gavage by the rat

Adult Zucker lean (Fa/?) female rats received a single 250 nmol oral gavage of 3H-labelled oleoyl-estrone in 0.2 ml of sunflower oil. After one hour, samples of arterial, portal and suprahepatic blood, and lymph were obtained and fractioned to determine the amount of radioactivity present in the form of free estrone, acyl-estrone and hydrophilic estrone esters in the blood of each vessel. Lipoprotein fractions (chylomicra + VLDL, LDL, HDL and lipoprotein-depleted plasma) were also analysed as well as the distribution of absorbed 3H-estrone in the intestine, specific organs and carcass. About one third of the oleoyl-estrone dose recovered was found in the tissues, mainly in the blood, the rest remaining relatively untouched in the intestinal content. High hypothalamic estrone uptake (compared with the rest of the brain) was observed. Data from non-radioactive estrone measurements showed a similar pattern of absorption and tissue distribution to that obtained by 3H-estrone tracking alone. In both cases, most of the estrone present in the intestinal lumen was absorbed as intact oleoyl-estrone, but a significant part was absorbed as free estrone. There is a net transfer of 3H-estrone into portal blood HDL, and part of the 3H-estrone is also loaded into lymph-carried chylomicra. A large share of free estrone is filtered by the liver, but most of the acyl-estrone absorbed passes unaltered. The oral administration of oleoyl-estrone results in significant absorption of the unaltered molecule, which is transferred to lymph-carried chylomicra and also directly to plasma HDLs. It may be inferred that the HDL fraction contains the physiological carrier of oleoyl-estrone in its role of ponderostat signal.